Another interesting thing I noted:
The island seems to heal people...Rose's cancer, Locke's legs, Jin's fertility problem (as far as know)...so I just find it interesting that an Other has a tumor. Does it only help people who are new to the island? Or perhaps the survivor's island is the only one that heals, and the other doesn't? Maybe the electromagnetic ...thing...going on with the button had something to do with it, but the tumor would have had to grow awful fast if that was the case.
Clarification for my last post: In respect to Desmond's clairvoyance about Locke helping, I was also thinking about Locke's hallucination with Boone, and Boone telling him he can't help Jack, Kate, and Sawyer...yet....and kind of melded the two ideas into one. I should have been more specific and clear
