S100A4 and neoplasm: Interestingly, the parallel increase we observed between fibronectin and S100A4 during mesothelial cell tumorigenesis (Nader et al., 2020), and the dramatic increase associated with the highest tumor invasiveness (Nader et al., 2018), resonate with findings reporting cooperation between fibronectin and S100 proteins in shaping the pre-metastatic niche in lung, liver, and bone (Paolillo and Schinelli, 2019).