Anti-PF4 antibody-mediated immunothrombosis gained major attention in 2021, when it was identified as cause of a rare but severe adverse reaction to adenoviral vector-based COVID-19 vaccines: vaccine-induced immune thrombocytopenia and thrombosis (VITT) [[35], [36], [37]]. This evidence concerns the gene PF4 and autoimmune thrombocytopenic purpura.