A common variant in the gene coding for the fat mass‐ and obesity‐associated protein (FTO) is known to predispose to obesity in adults and children.24 Recently, it has been shown that FTO, an RNA demethylase, plays an oncogenic role in AML in adults.25 It might therefore be biologically plausible that obesity and (certain types of) AML could have a common etiology in children as well. The gene discussed is FTO; the disease is Obesity.