Wt1 expression is unchanged in Vehicle versus GSI-IX-treated CAGG-CreERTM+/–; Wt1f/f transgenic mice. (A) Shown are merged micrographs of kidney sections following immunofluorescent labeling of kidney tissue sections of CAGG-CreERTM–/–; Wt1f/f, CAGG-CreERTM+/–; Wt1f/f, vehicle versus GSI-IX-treated CAGG-CreERTM+/–; Wt1f/f transgenic mice with Wt1 (Alexa Fluor 594-conjugated secondary antibody). Scale bars = 50 μm. (B) Relative transcript levels of Wt1 in primary podocytes of CAGG-CreERTM−−;Wt1f/f (control), CAGG-CreERTM+/−;Wt1f/f (mutant), vehicle-treated CAGG-CreERTM+/−;Wt1f/f, and GSI-IX–treated CAGG-CreERTM+/−;Wt1f/f transgenic mice. Bars represent the mean, error bars represent the SEM. CAGG-CreERTM−/−;Wt1f/f versus CAGG-CreERTM+/−;Wt1f/f: 1.1 ± 0.2 versus 0.4 ± 0.4, *P = 0.03, Student t-test; CAGG-CreERTM−/−;Wt1f/f versus vehicle-treated CAGG-CreERTM+/−;Wt1f/f mice: 1.1 ± 0.2 versus 0.4 ± 0.2, P = 0.07, Student t-test; vehicle-treated CAGG-CreERTM+/−;Wt1f/f mice versus GSI-IX–treated CAGG-CreERTM+/−;Wt1f/f transgenic mice: 0.4 ± 0.2 versus 0.4 ± 0.3, P = 0.93, Student t-test. n.s., not significant.