CCN2 and diabetes mellitus: Similarly, gene expression of the pro-fibrotic marker Ctgf was significantly increased overall by diabetes (P < 0.0001) and from 8 weeks of diabetes (P < 0.05) (Figure 6B), while Tgf-β was increased overall (P = 0.007) and after 16 weeks of diabetes (P < 0.05, Figure 6C).