Consistent with the reduced YAP1 KO tumor size and weight, the number of melanoma cells (α-SMA-negative, α-SMA-) that were Ki67-positive (Ki67+) and the number of cyclin D1-positive (cyclin D1+) cells were both decreased in YAP1 KO melanomas (Fig. 1P–U). Here, YAP1 is linked to melanoma.