If the allele in rs36084323 was G, then the promoter activity of the PDCD1 gene would be significantly higher than if the allele was A (50) and GG genotype of rs36084323 would had higher mRNA level of PDCD1 compared to AA genotype (48), which indicates that rs36084323 may involve in the development of RA through affecting the transcription level of PDCD1. Here, PDCD1 is linked to rheumatoid arthritis.