PTK2B and renal fibrosis: In addition, PYK2 is a crucial kinase to activate the PI3K/AKT and MAPK signaling pathways (Sun et al. 2008; Lev et al. 1995; Tokiwa et al. 1996; Zhu et al. 2018) and PYK2 phosphorylation can be upregulated in liver fibrosis and renal fibrosis (Kim et al. 2020; Sonomura et al. 2012).