Most research on MLL5 and HCF-1 has been done in proliferating cell lines to study cell cycle progression and cancer, but recent evidence suggests both MLL5 and HCF-1 can play a role in neuronal development49,50, and HCF-1 has been shown to play a role in the adult murine liver31, highlighting the need for additional work on the mammalian homologs in differentiated tissues. The gene discussed is KMT2E; the disease is cancer.