PTPNS1L is inferred to be protein tyrosine phosphatase, nonreceptor type substrate 1-like and potentially has similar but unknown functionality as some proteins in the same family as PTPN22. IGLVI-70, at the same locus of PTPNS1L, has been thought to be related to the immunoglobulin proteins, which have been found to play important roles in the RA pathology. Here, SIRPAP1 is linked to rheumatoid arthritis.