(A) Putative binding site of miR-219a-5p in 3′UTR of CD164 mRNA by prediction and generated mutant site at the CD164 3′UTR seed region binding to miR-219a-5p. (B) Real-time qPCR analysis of relative CD164 expression in lung tissue of lung cancer patients (n=30) and healthy controls (n=13). (C) Real-time qPCR analysis of relative CD164 expression in lung tissues of radiosensitive patients (n=12) and radioresistant patients (n=18). (D,E) A549-RR and H358-RR cells were transfected with miR-219a-5p and then relative mRNA and protein expression of CD164 were determined using real-time qPCR and Western blot. (F,G) The effect of miR-219a-5p on reporters of CD164-wt and CD164-mut in A549-RR or H358-RR cells was measured by luciferase reporter gene assay. (H,I) A549-RR or H358-RR cells were transfected with miR-219a-5p in combination with or without pcDNA-CD164. The cytotoxicity of 5-Gy irradiation was determined using CCK8 assay, *P<0.05.