These two genes are adjacent on the q arm of chromosome 2, binding with the same receptor of IL-1R1.52,53 Upregulation of IL-1α and IL-1β plays a key role in the development of periodontal inflammation through triggering cell chemotaxis, collagen destruction, and bone resorption.53 The presence of the T allele in the DNA sequence of IL-1α -889 and IL-1β + 3954 is significantly associated with early implant failure.54 According to a systematic review by Mohammadi et al,55 composite genotypes of IL-1α -889/IL-1β + 3953 were linked to the risk of PID. This evidence concerns the gene IL1A and pelvic inflammatory disease.