I don't think it would be all that controversial to make cancer cells, I think the issue is more that there are many kinds of cancer cells and not just one. The GiantMicrobes tend to be educational in nature, making the STD's is just as controversial as making cancer cells, but the STD's are individual organisms and therefore one shape fits one disease. From a purist standpoint cancer cells are not microbes, they are human body cells that have mutated and are growing out of control, I want them to stick with making microbes and not make more human cells. Someone who has or had cancer posted that they would be amused by a cancer cell GiantMicrobe, kind of looking the enemy in the eye type thing, but everyone would be different. I doubt my Bubbie who has cancer would appreciate it but there are those who would like it.
~~Nonpathogenic microbes are our friends~~