CCN4 and head and neck carcinoma: Upregulation of specific genes expressing Wnt ligands, such as Secreted frizzled-related protein 2 (SFRP2), Wnt2, Wnt5a, Wnt7a, or Wnt-1-induced secreted protein 1 (Wisp-1), leads to the transformation of normal fibroblasts into CAFs within the tumour stroma in various cancers, including colorectal, gastric, breast, and head and neck carcinomas.