MKI67 and melanoma: Additionally, to investigate the influence of vemurafenib on proliferation rates, melanoma cells re-isolated from BRAFWT (mOS-REpA11), BRAFV600E (mOS-REpSK-MEL-28) and keratinocytes re-isolated from non-melanoma skin equivalents were stained with the proliferation marker Ki67 (Fig. 5B, Fig. S2).