Despite the sensitivity of 4-color FISH in distinguishing melanoma from nevi, it is difficult to diagnose Spitz nevi due to its significant overlap with melanomas 71.To further improve the accuracy of diagnosis in morphologically ambiguous melanocytic neoplasms and Spitzoid neoplasms, Gerami et al proposes a new probe panel including 9p21 (CDKN2a), 6p25 (RREB1), 11q13 (CCND1) and 8q24 (MYC). The gene discussed is RREB1; the disease is melanoma.