However, recent studies have revealed that in this setting, upregulation of HIF-1α and HIF-2α activates distinct target genes and has contrasting effects on the growth of tumours (Maranchie et al, 2002; Kondo et al, 2002, 2003; Zimmer et al, 2004; Raval et al, 2005). The gene discussed is HIF1A; the disease is neoplasm.