CYP24A1 and non-small cell lung carcinoma: The joint effects between smoking and CYP24A1 rs2181874, CYP24A1 rs6068816, VDR rs10735810, and VDR rs1544410 suggest CYP24A1 rs6068816 and VDR rs1544410 mutations may reduce NSCLC susceptibility, whereas CYP24A1 rs2181874 and VDR rs10735810 mutations may increase NSCLC susceptibility, especially in the smoking population.