"这个不是书的主题"

you get it, then you don't get it?

It is about the right to profit.  Her family descedents want money now, but she gave her right up decades ago by accepting free treatments for cervical cancer.  The fame of immortal HeLa cells seems not sufficient consolation for her existing family - sounds like desperate people cashing out. 

千万不要为一点小钱去给人做医药实验 - I don't think anyone participates in medical experiments to earn big money 大钱. You give up your right to profit just like Henrietta did, although it is much safer now than 50 years ago