Transcription factors bound to the rat Bcl-2 promoter. Nuclear proteins bound to a 1040 bp (−1945 to −906) fragment of rBcl-2 promoter region P1 were pulled down from nuclear extracts of HEK293 cells and transcription factors were identified using TranSignal protein/DNA Array I (a) and Array II (b) (Panomics), as reported (Li et al., 2004). Top panels, hybridization signals; bottom panels, transcription factor identities. Box, Tcf signal; dotted box, E2F1 signal.