Transcriptional regulator; binds to the promoter region of Cp15. Also binds to its own promoter, thus having a probable autoregulatory role. Isoform I is found in embryos, pupae and adult somatic tissue; isoform II occurs in embryos, pupae, ovaries, testis and to a lesser extent in adult somatic tissue. Truncated N-terminus. Contaminating sequence. Potential poly-A sequence.