FZD6 and melanoma: The structural versatility of FZD receptors, particularly FZD3, FZD5, and FZD6, enables their interaction with non-canonical Wnt ligands such as Wnt5a and Wnt11, which are often overexpressed in cancers, including breast, colorectal, and melanoma (Corda and Sala, 2017; Brandt et al., 2018; Li C. et al., 2019).