By overall survival analysis of subgroups (Fig. 7, Figs. S1, S2), KLRK1 was found to have significant prognostic value in lung adenocarcinoma (P = 0.015), stage I/II (P = 0.03), older patients (P = 0.0052), and male (P = 0.0047). This evidence concerns the gene KLRK1 and lung adenocarcinoma.