ACTA1 and tongue squamous cell carcinoma: To confirm the role of PDGF-BB in the activation of fibroblasts, we used a PDGF-BB antibody blocker and PDGFR-β receptor inhibitor (CP673451), which attenuated the expression of α-SMA in the supernatant of tongue squamous cell carcinoma Cal-27-induced fibroblasts (Fig. 1F, H).