ADRA2A and cancer: Among the remaining 8 DEGs (ADRA2A, P2RX6, XCL2, XCL1, CCL7, TRIM54, TNFRSF18 and SPOCK1), the expression of ADRA2A, the top one, in KIRC based on individual cancer is lower than the normal tissues (Additional file 8: Figure S1 B), but patients with lower expressed ADRA2A have a better overall survival (OS) (Additional file 8: Fig. S1 C).