NTRK1 and melanoma: Also, amplification of microphthalmia-associated transcription factor (MITF) occurs in 15% of melanomas, activating mutation of the receptor tyrosine kinase, KIT proto-oncogene (KIT) (~20–25% of melanomas), and germline melanocortin 1 receptor (MC1R) variants are lineage-specific casual alterations in melanoma [18,19,20].