HOXB9 and adrenal cortex adenoma: HOX genes have been implicated in the initiation and progression of many cancers.11 Our and other studies have shown that Hoxb9 is expressed at the early stages of adrenal cortical development.14,33 To investigate if HOXB9 expression is associated with ACC, we analysed patient gene expression data from the Cochin cohort that contains normal adrenal (NAd), adrenocortical adenoma (ACA) and ACC samples.3 In this dataset, HOXB9 expression was higher in ACC samples with the difference with ACA being significant, but not with NAd (Fig. 1a).