In the past, consent was not used since medical regulation was still young and not widely enforced. In the case of Henrietta Lacks, the doctor did not give her the option to use her valuable cells for research, but as you said, that cell culture lead to mass scientific advancements in cancer research. Had Lacks checked “no” on a consent form when presented with on then it’ll be the end right there. The doctor will not be able to use Lacks’ cells for research and if it came to light that he/she did then he/she would be subject to penalties under law for unethical practices. I believe that the subject should have the choice to use his/her body in a clinical trial and that a consent form should have all the information the subject needs to know regarding the purpose of the trial and what is going to happen to their samples; in addition to any compensation they’ll receive from the experiment. In the case of Lacks, her cells ended up becoming valuable to the advancement of clinical research, so I think it is also up to the investigator, via compensation or other “deals”, to try and convince the subject to go forward with the study; to a certain extent. Being too pushy can be viewed as harassment and this may only deter the subject even further. In the same vein that the subject has the option to choose “no” I feel as though the investigator should have the same opportunity to convince the subject with ethical means (e.g. being completely honest with the purpose and procedure of the study without resorting to using misleading information); however, the final call should be from the subject and the investigator will simply have to move on and attempt to find other subjects should their desired subject say “no”.