P-LISA and ELISA experiments realized from non-tumor and tumor breast cell lines revealed that that tumor cells (MDA-MD-231 and Cal-51) harbored less Dnmt1/PCNA interactions and less 5-methycytosine (5 mC) than non-tumor cells (MCF10A) (Figures 2A and 2B). The gene discussed is PCNA; the disease is neoplasm.