PF4 and atherosclerosis: Furthermore, the negative control nOPRAH showed no activity, proving the importance of the free N‐terminus of OPRAH for receptor‐mediated monocyte recruitment.12 Peptide CKEY, which was able to disrupt non‐covalent PF4‐RANTES heterodimers and led to a decrease in atherosclerosis in a mouse model,5a was able to reduce monocyte adhesion with non‐covalent PF4‐RANTES heterodimers but not with OPRAH (Figure 5 C).