Studies in human UM have shown that less pigmented tumor regions are more metastatic and that BAP1-negative tumors exhibit a stem-like phenotype.1,2,86,87 Our findings raise intriguing questions about whether the progenitor cells observed in mitfa-deficient zebrafish are similarly predisposed to a more undifferentiated, stem-like phenotype, contributing to their enhanced transformation potential and aggressive tumor behavior. The gene discussed is BAP1; the disease is neoplasm.