ERRFI1 and lung cancer: Interestingly, stable ectopic expression of the wild-type EGFR increases the ERRFI1 mRNA level but not the protein level whereas ectopic expression of the L858R mutant EGFR, which is a common EGFR mutant in lung cancer, elevates both the mRNA and protein levels of Gene 33 in H1299 lung cancer cells [133].