Andrew's mom

I think for the sake of the movie, we're meant to assume it's some form of cancer. I've got a lot of experience in cancer research and health communication (i.e. advertising for heath concerns). From the way her illness is portrayed (harmful but vague), it's very likely to big one of "big & popular" ones.

In many cases in film, cancer is used as a HUGE umbrella term for any given illness needed to cause a character a slow and painful death. Many in the general public are aware that there are MANY forms of cancer as well as diseases similar to cancer. But, for the sake of the casual movie goer, we're either mean to a. Simply understand it's some form of fatal cancer or b. See symptoms of the random fatal disease and assume cancer. It's a trope that proves to be useful in tragic storytelling but also problematic for educating the general population of different diseases.

tl;dr Yeah, it was likely cancer because "When in doubt, assume cancer" if the film doesn't go into the disease at length

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