POSTN and breast cancer: Finally, WNT signaling activation by CAF-secreted HGF in colorectal adenocarcinomas or by CAF-secreted POSTN in head and neck squamous cell carcinoma and BC cells may also promote cancer stemness and further metastatic initiation (Vermeulen et al., 2010; Malanchi et al., 2011; Yu et al., 2018).