RAG gene expression analyzed in transcription factor KO VL3-3M2 cells. (A) Western blots of transcription factor protein expression in wild-type and KO VL3-3M2 cells. Bottom panels show loading controls. Approximate molecular weights are indicated in kilodaltons. Asterisk indicates a presumed nonspecific band detected by anti-GATA3. (B) Rag1 and Rag2 transcript abundance in wild-type and transcription factor KO VL3-3M2 cells assessed by RT-PCR. The data represent mean ± SEM of four to six independent experiments, with values for Rag1 and Rag2 normalized to those for Actb. **, P < 0.01; ***, P < 0.001; ****, P < 0.0001 by one-way ANOVA with Holm-Sidak’s multiple comparisons test.