IL2 and cutaneous mastocytosis: Albeit conducted on a small number of patients, the results of these initial studies are encouraging: i) serum ER-α methylation in stage IV CM patients was a negative predictor of overall and progression-free survival in patients treated with biochemotherapy (dacarbazine or temozolomide, cisplatinum, vinblastine, interferon-α2b, IL2, and tamoxifen) [123]; ii) serum RASSF1A methylation inversely correlated with overall survival and biochemotherapy response in CM patients [124].