I don't have a camp. I am merely here to point out flaws in your logic. So back on topic....
Cancer is entirely different. Cancer is caused by a mutation in a gene, and this mutation causes a change in the cell patterns and growth. The mutation is passed from parent to offspring. Are you saying a mutation in a gene is what causes heterosexuality and that's what is passed from parent to child? If so, a mutation in a gene can also cause homosexuality which means it is no longer a choice, and that it is also in the genes. Theres a contradiction for you.
The point is that my logic has no flaws. Based on my beliefs, my logic is flawless. The only possible way to claim otherwise is to apply someone else's beliefs. That is my point. Can you at least understand that based on the belief in my last post that there is no contradiction? I believe heterosexuality is inborn (i.e. in our genes) and I also believe there is no gene for sexual orientation. Based on those beliefs, there is no contradiction.
And as for your point about cancer, the fact that the gene mutates is irrelevant. The point is that there is no gene for cancer. So clearly there is more going on in genetics than simply what genes do and do not exist. Whether it be mutation, or errors in cell division/duplication, or any other factor, the fact is that which genes we have is not the end of genetics. And that is why I can say there is no sexual orientation gene and at the same time speak of something else that is genetic based on something outside of that limited understanding of genetics. So by bringing up mutation, you have actually proved my point that genetics is much more than just which genes are present.