HOXA9 and leukemia: Furthermore, we found that the imputed H3K27me3 scores also formed inverse patterns of gene association from H3K4me3, where genes such as HOXA9 that were rarely marked by H3K4me3 in 1° MPAL-1 leukemia cells showed elevated H3K27me3 scores in the majority of tumor cells (~55%) (Fig. 3j and Extended Data Fig. 9i).