PF4 promotes a VSMC synthetic phenotype. (A) VSMCs were treated with PF4 (1 µg/mL), and the expression of CNN1 and ACTA2 was determined by qRT-PCR (n = 4 ± SD; *P < .01 vs control). (B) Transwell chamber cell migration. VSMC migration after 18 hours to the basal aspect of a transwell chamber was determined in response to buffer or PF4 (1 µg/mL). Heparin was used as a negative control and tumor necrosis factor-alpha (100 ng/mL) as a positive control (n = 3 ± SD; *P < .01 vs control). (C) Cell proliferation. A total of 20 000 cells were plated, and the number of cells was counted 24 hours later using XTT staining (n = 3 ± SD; *P < .01 vs control).