TGFB1 and head and neck squamous cell carcinoma: For instance, TGFB1 secreted by CAFs is believed to be a promoter of DP (PRO+EMT, double-positive) phenotypes in various PDAC cell lines, and TGFB1, which has been proven to be directly involved in MAPK signaling in pancreatic carcinoma, hepatocellular carcinoma, head and neck squamous cell carcinoma, as well as lung carcinoma (Liu et al., 2014; Principe et al., 2017; Tang et al., 2017; Wang et al., 2018).