Genomic organization and expression of HOXA genes in leukemia cells. (A) Transcript map of the human HOXA cluster on chromosome 7p15.3. The map is drawn according to scale. Transcript direction is indicated by an arrow. (B) Hoxa expression pattern in a murine MLLENL-transformed cell line. Transcript levels were quantitatively determined by q-RT PCR corrected for amplification efficiency across primer pairs and normalized to actin. Given are average values and standard deviations for triplicates with a relative expression level of one unit (2⁰) corresponding to a ΔCt = 20 with respect to actin. (C) Correlation of HOXA gene expression across a sample set of 285 cases of AML.²⁷  Shown are HOXA genes with a significant correlation to HOXA1 expression (top line) across samples as determined by Oncomine, an expression database search and analysis tool (http://www.oncomine.org). Each line of the heat map corresponds to a HOXA gene as indicated to the right, and each column is indicative for a single patient sample. “corr” indicates correlation coefficient, indicating the degree of concordant expression within a single patient sample.