MYC and leukemia: Gao et al [14] showed that c-MYC down-regulated expression of miR-23a and miR-23b and bound to a cognate site upstream of the miR-23b locus in a B lymphoma cell line, others have provided evidence for a feedback loop involving direct negative regulation of c-MYC by miR-24 [13], [31], and there is growing evidence for regulation of miRs by c-MYC as well as regulation of c-MYC by miRs in cancers including leukemia [32], [33].