Sporadic cSCC arising in patients never treated with vemurafenib (n = 15) contained substantially greater expression of phospho-JNK (p=0.013; Figure 4A,E) and cleaved caspase-3 (p=0.042; Figure 4C,E) as compared to lesions arising in vemurafenib-treated patients (n = 16; Figure 4B,D,E). Here, MAPK8 is linked to skin squamous cell carcinoma.