These include the validation in larger case series of the reported association between specific HLA alleles and the risk of developing these autoimmune disorders, the search for possible specific blockers of the HLA presenting PF4-derived peptides potentially preventing inappropriate immune responses [77], the clonality of pathogenic anti-PF4 antibodies, the intracellular signaling pathways involved in the detrimental effects of anti-PF4 antibodies, and the effects of persisting anti-PF4 antibodies on future exposure to heparin, adenovirus-based vaccines, or viral infections. Here, PF4 is linked to viral infectious disease.