Identification of significantly expressed probe sets and subsequent validation with real-time RT-PCR. Expression profiles for selected transcripts in vehicle- or DEX-treated chondrocytes are confirmed with real-time RT-PCR at 0, 6, 12 and 24 hr time points. Indian hedgehog (Ihh), tissue inhibitor of matrix metalloproteinase 4 (Timp4), cyclin-dependent kinase inhibitor 1C (Cdkn1c, p57), integrin beta like 1 protein (Itgbl1), glucocorticoid receptor (Nr3c1), integrin beta 1 (Itgb1) and kruppel-like factor 15 (Klf15) microarray data are shown on the left at the 6 and 24 hr time points and corresponding real-time expression values are shown on the right. P-values less than 0.01 are deemed significant. Specifically, Ihh, Timp4, Itgbl1 and Klf15 exhibit significant differences between the 6 and 24 hr time point and between treatments. Dotted lines indicate the control and solid lines denote DEX treatment.