HOXC5 and leukemia: However, it is notable that in many of the cell lines where miR-615 is found, including the lymphoblastoid cell line GM12878 and the leukaemia-derived K562 cell line, there is little to no expression of HOXC5. To validate the observation that HOXC5 is not expressed in K562 cells, we constructed a de novo transcriptome assembly for this cell line using raw data from the ENCODE Consortium [29] and again did not find evidence for HOXC5 expression (Additional file 8: Supplement S8).