There were four errors in both the online and the print versions of this paper. In the paragraph `Extracellular matrix synthesis is controlled by HIF-1α under hypoxia' in Results on p. 1823, line 10, it should read`Significantly less extractable proteoglycans were detected in HIF-1α-null than in wild-type cultures after 44 hours exposure to 0.5%oxygen (Fig. 5B)'.
On p. 1824, the legend to Fig. 5, lane 3, should read `(A) Analysis of aggrecan gene expression: Bars represent -fold changes of aggrecan mRNA levels in HIF-1α-null cells compared with wild-type levels (normoxic and hypoxic wild-type expression taken as 1.0, respectively)'.
On p. 1824, the legend to Fig. 6, lanes 12-13, should read `(normoxic and hypoxic wild-type expression taken as 1.0, respectively)'.
On p. 1825, the legend to Fig. 7, lane 7 should read `(untreated normoxic and hypoxic expression taken as 1.0, respectively)'.
We apologize for any inconvenience caused.
