TGIF2 and cancer: To further understand whether phosphorylation of TGIF2 by EGFR–RAS–ERK is important for EGFR promoted stemness of cancer cells, we next compared the functions of wild type-TGIF2 (TGIF2WT) and phosphorylation-deficient TGIF2 mutants (i.e., T182A and T186A, or TGIF2AA for short, Fig. 5k) in promoting the stemness of LUAD cells.