CREB1 and melanoma: Furthermore, it reduced cellular melanin content and intracellular tyrosinase activity in B16F10 melanoma cells by downregulating microphthalmia-associated transcription factor (MITF), cAMP-dependent protein kinase (PKA), cAMP response element-binding protein (CREB), p38, c-Jun N-terminal kinase (JNK), β-catenin, glycogen synthase kinase-3β (GSK3β), and protein kinase B (AKT) proteins, while upregulating extracellular signal-regulated kinase (ERK) and p-β-catenin.