FOS and skin basal cell carcinoma: Consistent with this observation, siRNA knockdowns of c-Jun, JunB, JunD, or FosL2 in BCC cells resulted in significant decrease in Gli1 expression, with JunD knockdown having the biggest effect, while knockdown of Fos or FosB did not change Gli1 expression (Fig. 3f, Supplementary Fig. 3l).