STK11 and melanoma: In BRAF‐mutant melanoma cells, activated BRAF constitutively phosphorylates ERK and ribosomal s6 kinase (RSK) which phosphorylate LKB1 (Ser325 and Ser428) and in turn suppress its capability to activate AMPK in melanomas (Esteve‐Puig et al., 2009; Zheng et al., 2009).