Therefore, we hypothesize that Wnt signaling may be one of several components that maintain lin-1 expression in the VPCs before induction, such that while overexpression of ΔNTBAR-1 upregulates lin-1 expression, reduction of Wnt signaling, such as in a bar-1 ( ga80 ) mutant, does not reduce lin-1 expression enough to cause an overinduction phenotype.
Source: wiktionary