A, primary bovine keratocytes were exposed to various agents as in Table 1 in the presence (dark bars) or absence (open bars) of 1 ng/ml TGFβ. HAS2 mRNA was determined by qRT-PCR after 6 h of exposure. Error bars show standard deviation of triplicate analyses. mRNA levels in untreated cells were set = 1. B, shows the ratio of mRNA abundance for samples in A (TGFβ treated/no TGFβ). HSHS, 2% heparin-stripped horse serum; BSA, 1 mg/ml Albumax, lipid-rich bovine serum albumin; IGF, 50 ng/ml insulin-like growth factor 1; FGF, 10 ng/ml fibroblast growth factor-2; PDGF, 10 ng/ml platelet-derived growth factor BB.