MKI67 and cancer: Both cell lines had medium positive staining for the proliferation marker Ki67 (an average of 47.9 ± 7.9% and 15.5 ± 4.7%, respectively) and a high positive staining for the cancer biomarker BMI1 (an average of 82.7% and 64.6%, respectively) (Additional file 2: Figure S2D, E).