Imagine something small enough to float on a particle of dust that holds the keys to understanding cancer, virology, and genetics.
想象一种小到可以漂浮在一粒灰尘上的东西，它是人们理解癌症、病毒和基因的关键之物。
Luckily for us, such a thing exists in the form of trillions upon trillions of human lab-grown cells called HeLa.
幸运的是，有亿万个这样的东西以人类实验室培育细胞的形式存在，它的名字叫海拉细胞。
Let's take a step back for a second.
让我们先退一步来看。
Scientists grow human cells in the lab to study how they function,
科学家在实验室中培育人类细胞来学习它们如何起作用，
understand how diseases develop, and test new treatments without endangering patients.
理解疾病是如何产生的，并在避免危害病人的情况下试验新研制的药物。
To make sure that they can repeat these experiments over and over, and compare the results with other scientists,
为了确保科学家可以重复这些试验以及与其他科学家比较试验结果，
they need huge populations of identical cells that can duplicate themselves faithfully for years,
他们需要大量相同细胞的储备，这些细胞需要年复一年的不断分裂，
but until 1951, all human cell lines that researchers tried to grow had died after a few days.
但1951年前，所有科学家尝试培育的人类细胞在几天之内就会死亡。
Then a John Hopkins scientist named George Gey received a sample of a strange looking tumor: dark purple, shiny, jelly-like.
后来，一位约翰霍普金斯医院的研究者George Gey收到了一份样子奇怪的肿瘤样本：深紫色、有光泽的、胶状的物体。
This sample was special. Some of its cells just kept dividing, and dividing, and dividing.
这是个十分特殊的样本，其中的一些细胞不断、不断、不断的分裂。
When individual cells died, generations of copies took their place and thrived.
当单个细胞死去时，它一代代的复制品代替了它，并且继续兴盛生长。
The result was an endless source of identical cells that's still around today.
最后便有了如今还存在的“无尽”相似细胞。
The very first immortal human cell line.
第一种永生的人类细胞系。
Gey labeled it 'HeLa' after the patient with the unusual tumor, Henrietta Lacks.
Gey将它命名为海拉细胞，名字来源于携带这不寻常肿瘤的病人Henrietta Lacks。
Born on a tobacco farm in Virginia, she lived in Baltimore with her husband and five children.
她出生于弗吉尼亚州的一个烟草农场，与她的丈夫和五个孩子住在巴尔迪莫。
She died of aggressive cervical cancer a few months after her tumorous cells were harvested, and she never knew about them.
她在她的肿瘤细胞被获取后的几个月后死于侵略性宫颈癌，但她从不知道自己的细胞被移去。
So what's so special about the cells from Henrietta Lacks that lets them survive when other cell lines die?
Henrietta Lacks的细胞到底有什么特别之处，能让它在其他细胞系都死去时可以单独生存下来？
The short answer is we don't entirely know.
简单来说，我们也不是很清楚。
Normal human cells have built-in control mechanisms.
正常的人类细胞之中有调节机制。
They can divide about 50 times before they self destruct in a process called apoptosis.
在它们分裂大约五十次时就会以细胞凋亡的形式自我毁灭。
This prevents the propagation of genetic errors that creep in after repeated rounds of division.
这种机制阻止了在多次分裂后可形成的基因缺陷的传播。

But cancer cells ignore these signals, dividing indefinitely and crowding out normal cells.
但是癌细胞会无视这种信号，永无止境的分裂，并将正常细胞挤走。
Still, most cell lines eventually die off, especially outside the human body.
但是，一般的细胞系，特别是在人体外的，最终会死去。
Not HeLa, though, and that's the part we can't yet explain.
海拉细胞就不同了，可是，这也是我们无法解释的地方。
Regardless, when Dr. Gey realized he had the first immortal line of human cells, he sent samples to labs all over the world.
不管怎样，当Gey博士意识到自己发现了第一条永生人类细胞系时，他将这些样本寄送到了世界各地的实验室。
Soon the world's first cell production facility was churning out 6 trillion HeLa cells a week,
马上，世界上第一个细胞生产设备在一个星期中生产出了六万亿个海拉细胞，
and scientists put them to work in an ethically problematic way,
可是在利用海拉细胞的过程中，科学家没有遵守伦理标准，
building careers and fortunes off of Henrietta's cells without her or her family's consent, or even knowledge until decades later.
他们在拓展事业与收获财富前并没有获得Henrietta和她家人的同意，甚至在几十年过后才告诉他们。
The polio epidemic was at its peak in the early 50s.
小儿麻痹症的蔓延度在五十年代到达了顶峰。
HeLa cells, which easily took up and replicated the virus, allowed Jonas Salk to test his vaccine.
海拉细胞很快占据并复制了这病毒，让Jonas Salk得以试验他的疫苗。
They've been used to study diseases, including measles, mumps, HIV, and ebola.
海拉细胞被用于对疾病的研究，其中包括麻疹、腮腺炎、艾滋和伊波拉病毒。
We know that human cells have 46 chromosomes because a scientist working with HeLa discovered a chemcial that makes chromosomes visible.
我们所知道的人类细胞拥有46条染色体，是因为一位科学家利用海拉细胞发现了一种化学物质，能使染色体可见。
HeLa cells themselves actually have around 80 highly mutated chromosomes.
海拉细胞自己拥有大约八十条高度变异的染色体。
HeLa cells were the first to be cloned. They've traveled to outer space.
海拉细胞是第一个被克隆的细胞。它们还曾到过外太空。
Telomerase, an enzyme that helps cancer cells evade destruction by repairing their DNA, was discovered first in HeLa cells.
端粒酶，这个酶会修复癌细胞的DNA，避免癌细胞的死亡，在海拉细胞中被第一次发现。
In an interesting turn of fate, thanks to HeLa,
还有一场有趣的命运的转折，感谢海拉细胞，
we know that cervical cancer can be caused by a virus called HPV and now there's a vaccine.
我们才得知宫颈癌是由一种叫做人乳头状瘤病毒的病毒造成的。
HeLa-fueled discoveries have filled thousands of scientific papers, and that number is probably even higher than anyone knows.
现在也有了针对其疫苗的几千份海拉细胞引导的科学论文，这个数字很有可能比我们知道的还多。
HeLa cells are so resilient that they can travel on almost any surface: a lab worker's hand, a piece of dust,
海拉细胞非常有弹性，这让他们可以在任何表面上流动：在一个实验室工作人员的手上，在一片灰尘上，
invading cultures of other cells and taking over like weeds, countless cures, patents and discoveries all made thanks to Henrieta Lacks.
侵入其他细胞的培养，向杂草一样蔓延并代取无数种疗法，专利和发现，这些都要感谢Henrietta Lacks。