MAPK6 and melanoma: Although the specific signaling mechanisms involved in the regulation of ERK3 have been studied by us and others and provided tissue-specific insights into this atypical MAPK function (Bogucka et al., 2021; Elkhadragy et al., 2020; El Merahbi et al., 2020; Elkhadragy et al., 2017; Long et al., 2012; Sauma and Friedman, 1996), many aspects of ERK3 biology such as its role in suppressing melanoma cell growth and invasiveness remain elusive (Chen et al., 2019).