CCN1 and skin basal cell carcinoma: Since their role in basal cell carcinoma is poorly understood, Quan et al. [28], in a series of experiments, showed that the YAP upregulates CCN1 and CCN2 in BCC tumor cells which results in elevated CCN1 and CCN2 mRNA levels, and modulates healthy keratinocyte proliferation via CCN1 [28].