One goal of modern medicine is to provide cancer treatments that impact cancer cells while leaving healthy cells unaffected. To do this, much work has gone into creating drugs that inhibit the activity of proteins or other factors that are specifically required for cancer cell growth. Leukaemias are a type of blood disease that are more prevalent in children or the elderly. There is a dramatic difference in survival rates for children diagnosed with leukaemia. Over 90% of children (>1 years) can expect to survive. By contrast, just 60% of infants (<1 years) can expect to survive. Many of these infant leukaemias contain an MLL-AF4 genetic mutation, which drives a particularly aggressive disease that often becomes resistant to treatment. Novel therapeutic strategies are therefore urgently needed to better treat and cure infant MLL-AF4 leukaemias. In collaboration with several other groups, recent work in our lab has identified unusual patterns of gene regulation in MLL-AF4 leukaemias that are helping us develop new therapies for infant leukaemias. The overall hope is to one day have cancer treatments that are effective as well as being relatively non-toxic.