In this study, we demonstrated that carboplatin-resistant p53-null ovarian cancer cells (SKOV3; p53H179R) are highly accumulated in the G2/M phase of the cell cycle, displaying an elevated level of ABCB1 together with elevated stemness-related gene expression and highly proliferative properties compared to non-resistant SKOV3 and carboplatin-resistant p53-expressing cancer cells (OVCAR3; p53R248Q). The gene discussed is ABCB1; the disease is ovarian carcinoma.