AXL and melanoma: These subpopulations of ‘MITF‐negative’ cells, which are contained within a subset of melanoma cell populations originally identified by Hoek and colleagues (Hoek et al., 2006), are characterized by the expression of the non‐canonical Wnt ligand WNT5A and the receptor tyrosine kinase AXL (Dissanayake et al., 2008; Konieczkowski et al., 2014; Muller et al., 2014; Sensi et al., 2011).