In the genomic region for IBDV response on chromosome 9, two putative candidate genes, protein tyrosine phosphatase non-receptor type 1 (PTPN1) and nuclear factor of activated T-cells cytoplasmic calcineurin-dependent 2 (NFATC2), have been associated with efficient host response to viral infections in other species [70–72]. This evidence concerns the gene PTPN1 and viral infectious disease.