HOXA4 and lung cancer: Recent work in lung cancer cell lines has demonstrated that expression of HOXA4 inhibits cell survival via inhibition of the Wnt signalling pathway,27 a pathway known to be activated in CLL,28 and which promotes the survival of leukaemic cells.29 Negative regulators of Wnt signalling are epigenetically silenced in CLL,30 and our study may implicate HOXA4 as another silenced inhibitor.