PF4 increases KLF4. (A) Protein expression. HCASMCs were treated with PF4, and KLF4 expression was determined by western blot (representative). (B) Quantification of band density relative to actin control (n = 3 ± SD; *P < .01 vs 0). (C) PF4 increases HCASM cell KLF4 mRNA expression. VSMCs were treated with PF4, and KLF4 mRNA was quantified by qRT-PCR (n = 3 ± SD; *P < .01 vs 0).