For example, the rash and paronychia incidence of afatinib, a second-generation EGFR-TKI, was recorded as high as 89.1% and 56.8% [50, 51], while the corresponding data the first-generation EGFR-TKI (gefitinib and erlotinib) was generally lower (rash was 66.2% ~ 73% and paronychia was 4%—13.5%) [52, 53]. This evidence concerns the gene EGFR and paronychia.