MKI67 and brain neoplasm: Thus, the revealed correlation between the ratio of overall neutral lipid/cholesterol in blood plasma and the immunohistochemical marker of cell proliferation activity, the Ki-67 nuclear protein, is very probably due to the accumulation of lipid droplets in the malignant cells and due to the increase in the permeability of the blood–brain barrier resulting from the growth and increasing degree of anaplasia of the brain tumor.