For one time I was very into studies on skin cancer, especially melanoma. They are among the most responsive cancer types to immunotherapies because they carry distinctive antigens for immune system to recognize (the first thing that drew me into the subject). They are highly-associated with UV light; the association is also determined by individual genetic background. As asian, for example, I never worried too much about being sun-sensitive or getting skin cancer from a little bit too much sun bath. (Sidenote: my previous post touched upon some related mechanisms. ) However, "my whole world"/my skin changed since this past September- I've been constantly experiencing rashes, swell, and flaking on my face. That was really abnormal to me because my skin was never sensitive. For as long as 2 months, I had 4 reactions in total, and each time it got worse! That was how my story began- How I finally figured out my "photo-allergy" to my sunscreen. Stage 1: Im...