ATF6 and skin squamous cell carcinoma: To examine this question, JWF2 cutaneous squamous cell carcinoma (cSCC) and B16F10 melanoma cell lines were preincubated with the PERK inhibitor, GSK260414, the IRE1 inhibitor, STF083, or the ATF6 inhibitor, Ceapin A7, and the cells were then treated with 15d-PMJ2.