BTLA and rheumatoid arthritis: Two studies indicated that BTLA gene polymorphism contributes to the occurrence and progression of rheumatoid arthritis.[15,16] The research of Fu et al. suggests BTLA gene polymorphisms might be correlated with susceptibility and prognosis of sporadic breast cancer in Chinese women.[17] During the past few years, increasing studies have found SNPs in BTLA are a risk factor for tumorigenesis and tumor progression, especially rs1982809.