Significantly higher CD68 frequencies were found in PMF BM (mean CD68-positive cells: 27% per all nuclear cells within bone marrow spaces) compared to CML (mean 2% CD68-positive cells) (p = 0.017, FDR = 0.028), ET (mean 6% CD68-positive cells) (p < 0.001, FDR = 0.008), PV (mean 13% CD68-positive cells) (p < 0.001, FDR = 0.015), and reactive BM (mean 5% CD68-positive cells) (p < 0.001, FDR = 0.003) (Figs. 2 and 3). Here, CD68 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.