These results indicated that tricin distinctly inhibited the SRC phosphorylation and the protein expression of JUNB, FOSB, and the immune checkpoint PD-L1, along with the classic proteins in the MAPK pathway, in a dose-dependent manner in PDGF-BB-stimulated KRASG12C-mutant NSCLC cells. The gene discussed is SRC; the disease is non-small cell lung carcinoma.