To confirm high YAP1 activity in MAPKi-resistant MITFlow/AXLhigh melanoma cells independent from YAP5SA engineered YAP1 activation, we used a YAP1/TAZ-reporter luciferase assay in melanoma cell lines with spontaneously acquired resistance to a BRAFV600E inhibitor (SKMEL28R, A375R1, A375R2) or the combination of a BRAFV600E and a MEK inhibitor (A375DR) [23, 31]. Here, YAP1 is linked to melanoma.