FLT1 and melanoma: According to the phenotype switching model, metastasis formation is the result of tumour transition from a proliferative to an invasive phenotype.32 An online gene expression‐based tool developed for predicting melanoma cell phenotype (ie Heuristic Online Phenotype Prediction, HOPP) is available and has identified a set of genes that characterizes these two different melanoma phenotypes.33 By using the HOPP algorithm, we have evaluated VEGFR‐1 expression in 220 melanoma cell lines and short‐term cultures grouped on the basis of their proliferative or invasive behaviour.