To investigate the effect of ZA on myeloid differentiation in vitro, total bone marrow cells were cultured with M-CSF or 30% tumour supernatant in the presence or absence of ZA for 6 days using similar culture conditions as described by others (Wan et al, 2007, 2009; Tsagozis et al, 2008). This evidence concerns the gene CSF1 and neoplasm.