Hnf1a (Tcf1) has been shown to activate the Liver-type pyruvate kinase (pklr) gene in rat INS1 cells (Wang et al. 1999). It has been shown to bind the Pklr gene in mouse islets by chromatin immunoprecipitation, and decreased expression is observed in Hnf1a-/- islets (Parrizas et al, 2001). Plkr expression in the developing pancreas in vivo is lost by embryonic day 18.5 in mice lacking a functional Hnf1a gene (Boj et al. 2001).