PDCD1 and systemic lupus erythematosus: We therefore, aimed to study four identified PDCD1 SNPs, i.e., PD1.1 (G>A; promoter region), PD1.3 (G>A; intron 4), PD1.5 (C>T; exon 5) and PD1.6 (G>A; 3'-UTR), in our Malaysian SLE cohort.