Figure 3. Quantitative real-time polymerase chain reaction. Quantitative real-time polymerase chain reaction of the eight verified genes using glyceraldehydes 3-phosphate dehydrogenase (GAPDH) as endogenous control showed that bone morphogenetic protein 4 (BMP4; A), cofilin 1 (CFL1; B), JAW1-related protein (MRVI1; C) were increased by 1.6, 3.3, and 11 fold, respectively, whereas actin, alpha 2 (ACTA2; D), gene rich cluster, and C 10 gene (GRCC10; E), tissue inhibitor of metalloproteinase 3 (TIMP3; F), tissue inhibitor of metalloproteinase 1 (TIMP1; G), and somatostatin receptor 1 (SSTR1; H) were decreased by 4.5, 2.7, 14, 8.5, and 1.8 fold, respectively in keratoconus relatively to norma l cornea.