EGFR and Skin rash: Few patients in our study had ≥ grade 2 rash even in the H group, a finding that was consistent with that in the study by Rukazenkov et al. They found that gefitinib was significantly accumulated in tumor tissue; thus, the plasma concentration was lower than that of erlotinib, providing the concentration needed at its target to achieve effective EGFR inhibition in the tumor while causing less skin toxicity than erlotinib7.