PTPRN and type 1 diabetes mellitus: The other established autoantibodies are islet cell autoantibodies (ICAs), a protein tyrosine phosphatase with unknown function in the islet cell.[69–71] ICA has been found in the majority of type 1 diabetics of recent onset, with the percentage falling rapidly thereafter, and is associated with an increased incidence of the HLA B-8 haplotype.[65] GAD65 and IA-2 antibodies are present in approximately 26% cases of type 1 diabetes in North India.[58]