CYP26B1 and hypervitaminosis A: In fact, we previously identified elevated Vegfa (and Cyp26b1) levels in bone tissue of rats with hypervitaminosis A, using microarray analysis (Lind et al., 2012) and earlier studies show increased production/release of Vegfa from mouse osteoblasts and other cell types/tissues upon RA treatment (Harada et al., 1994; Maeno et al., 2002; Tanabe et al., 2004; Wu et al., 2011; Tan et al., 2015).