Compared with baseline after ET, elevated PF-4 was detected in 2 studies within both patient and control groups,[13,19] in 1 study within patient group alone,[24] and in 1 study within control group alone.[20] The expression level of PF-4 was decreased in CAD patients compared to controls in 2 studies,[19,20] increased in 1 study[24] and unchanged in 3 studies following ET.[13,21,23]. Here, PF4 is linked to coronary artery disorder.