Transcription factor that plays an important role in cellular development and cell survival (PubMed:7862533). Recognizes and binds to the DNA sequence 5'-GCG(T/G)GGGCG-3' (PubMed:17716689, PubMed:25258363, PubMed:7862533). Regulates the expression of numerous target genes, including EPO. Plays an essential role for development of the urogenital system. It has a tumor suppressor as well as an oncogenic role in tumor formation. Function may be isoform-specific: isoforms lacking the KTS motif may act as transcription factors (PubMed:15520190). Isoforms containing the KTS motif may bind mRNA and play a role in mRNA metabolism or splicing (PubMed:16934801). Isoform 1 has lower affinity for DNA, and can bind RNA (PubMed:19123921). {ECO:0000269|PubMed:15520190, ECO:0000269|PubMed:16934801, ECO:0000269|PubMed:17716689, ECO:0000269|PubMed:19123921, ECO:0000269|PubMed:19416806, ECO:0000269|PubMed:25258363, ECO:0000269|PubMed:7862533}. This is the function of ENSG00000184937 (WT1, WT1 transcription factor).