MAPK1 and melanoma: In both cell lines, dasatinib reduced the phosphorylation of p38, a kinase known to phosphorylate p53, with complete loss of p-p38 observed in SK-MEL-2 cells (Fig. 4d) Loss of p53 phosphorylation might therefore be an interesting candidate for a kinetic marker of dasatinib responsiveness in melanoma, pending more comprehensive validation in future studies.