CEBPA interacts with E2F1 (Keeshan et al. 2003) bound to the promoter of the MYC gene (Johansen et al. 2001, D'Alo' et al.2003, also inferred from mouse homologs). CEBPA inhibits the transcriptional activation activity of E2F1 and inhibits transcription of MYC. By inhibiting MYC, CEBPA inhibits cell proliferation and promotes differentiation (Johansen et al. 2001, D'Alo' et al. 2003). The N terminus of the p42 isoform of CEBPA is required for interaction with E2F factors (inferred from mouse homologs) and therefore the p30 isoform, which lacks the N terminus, has a reduced ability to inhibit proliferation.