MAPK1 and cancer: Also among associations identified in the MAPK pathway are associations between BRAF(A) mutations and increased dependencies on other downstream members of the MAPK signaling pathway including MAP2K1, MAPK1, MITF, and DUSP4. Associations with MAP2K1, MAPK1, and MITF are consistent with previous reports on conditional dependency on these genes in BRAF(V600E) melanoma.70, 71, 72 The association with increased dependency on DUSP4 is intriguing because there are conflicting reports regarding DUSP4’s role in cancer.