By relapse free survival analysis of subgroups (Fig. 8, Figs. S3, S4), KLRK1 was found to have significant prognostic value in lung adenocarcinoma (P = 0.0094), stage I/II (P = 0.0076), older patients (P = 0.0072), and male (P = 0.0033). Here, KLRK1 is linked to lung adenocarcinoma.