Kaplan-Meier analysis was used to examine the relationships between CTLA4 SNPs and bacterial or viral infection (Table S2 and Table S3); no significant differences in the genotype frequencies of rs733618, rs4553808, rs5742909, rs231775 or rs3087243 existed between the bacterial infection and non-bacterial infection groups (Figure S1). This evidence concerns the gene CTLA4 and viral infectious disease.