Is the sentence grammatically correct? Or flawed?

Deja review?!

Today's hypotheses deem the primary mechanism that the special hormone increases the breast cancer risk is that it facilitates cell proliferation.

Today's hypotheses suggest that the primary reason that the special hormone increases breast cancer risk is that it facilitates cell proliferation. (or "may increase" if it is not yet reasonably certain that it does increase risk)

Yeah, I should have put "that" before "the primary mechanism".

Use "may incease"? Jack, haven't you seen through that fact "that the special hormone increases breast cancer risk" stands as a truth. To investigate the mechanism of the truth, the researchers found that the mechanism is that it facilitates cell proliferation.

Comp problem. I clicked "Ask a Question", and there was no response, so I clicked again. Only to find later that there have already been two same threads there.

And worse. when I tried to click the redundant one, A2K told me that an error occurred and has cost the life of a hamster blah blah blah..."

The stupid computer cheated us. The problem had once cost my ID in a UK forum to be banned because a mod there deemed my behavior "spamming."

Yeah, those mods sure are an anal bunch, aren't they, Ori?