In conclusion, the following were observed: (1) great differences in frequencies of ERAP1 SNPs between Chinese and Polish healthy populations; (2) four ERAP1 polymorphisms that were found strongly associated with NSCLC in Chinese, but not in Poles; and (3) an association (albeit weak) of two ERAP1 polymorphisms with distinct histopathological types of NSCLC in Poles, but not in Chinese. This evidence concerns the gene ERAP1 and non-small cell lung carcinoma.