Unexpectedly, some imprinted genes exhibited higher expression in the male cell lines (Fig. 7) including the maternally expressed Cdkn1c, Phlda2, and Slc22a18. To see whether this was due to loss of imprinting, we performed allelic expression assays and observed monoallelic expression from the appropriate parent of origin allele for the BC cells, i.e., C57BL/6 allele, and maternally biased expression for the CB cells (Additional file 8: Figure S3). The gene discussed is CDKN1C; the disease is breast cancer.