CHEK1 and melanoma: Across 674 samples from 11 melanoma studies, the authors identified genetic interactions between KIT alterations and mutations in cell cycle checkpoint genes ATM, ATR and CHEK1. In contrast, no interaction was identified between these cell cycle genes and BRAF or NRAS mutations, suggesting that perturbations in DNA damage signaling may be of importance specifically in KIT-mutated melanomas (28).