NTRK1 and melanoma: TrkA mediates melanocyte and melanoma cell responses to neurotrophic factors [5,6], the gene that encodes TrkA, NTRK1, is frequently amplified in CMMs, increased TrkA expression and intracellular activation have been positively correlated with CMM progression and poor outcome [7,8,9,10] and TrkA fusion oncogenes have been detected in CMMs and spitzoid melanomas [11,12].