MITF-directed RNAi did not affect c-MYC mRNA expression in MITF-negative melanoma (A375) and non-melanocytic tumor cells (MCF7 breast cancer and U2OS osteosarcoma cells) in contrast to MITF-dependent 501 mel cells ruling out siRNA-mediated off-target effects on c-MYC (Supplementary Figure 6c). Here, MITF is linked to osteosarcoma.