BRAF inhibition induces a significant decrease in cell volume in treated human melanoma tumors. A–B, A significant reduction in mean cytoplasmic volume is observed in the majority of biopsies of patient tumors after commencement of BRAFi therapy C, without a significant decrease in mean number of nuclei per HPF. D, The majority of cases showed a large increase in average intercellular distance after commencement of therapy. E, a significant increase in number of apoptotic nuclei was not observed in the majority of cases. *, p < 0.05; **, p < 0.01; ***, p < 0.001.