PTPRC and melanoma: We first confirmed by flow cytometry that NK cells can be detected in patient melanoma BrM obtained from two different patients (1.18% and 1.45% of intratumoral CD45+ cells, respectively), with majority of NK cells expressing the activation markers NKp46 (76.4% and 88.1% of NK cells, respectively) and CD69 (93.2% and 98.2% of NK cells, respectively) (online supplemental file 1A), as well as in intracranial tumors in the two-site BrM model established with B16 melanoma cells (online supplemental figure 1B).