Growing evidence suggests that calpain is associated with viral infection; in particular, its protease activity mediates the proteolytic modification of human cytomegalovirus UL112-113 proteins and enterovirus polyprotein, and calpain-1 interacts with the CD163 receptor to facilitate porcine reproductive and respiratory syndrome virus (PRRSV) uncoating in early endosomes (37, 38). Here, CAPN1 is linked to viral infectious disease.