Common findings in the cases described were the presence of elevated levels of D-dimer and antibodies against PF4 (identified by ELISA-based assays) and protein S, combined with thrombocytopenia but also hypofibrinogenemia, factor XIII deficiency, MTHFR C677T heterozygosis, and folate deficiency with increased levels of homocysteine and/or antiphospholipid antibodies [68,70,71,72,186,203,204,205,206]. Here, PF4 is linked to Thrombocytopenia.