Correlation between the numbers of CD26⁺ SCs and CML scores. (A-B) In 27 patients with CML (BM samples, n = 26; PB, n = 1), the percentage of CD26⁺ SC (of all CD34⁺/CD38⁻ cells) and CD26⁺ progenitor cells (of all CD34⁺/CD38⁺ cells) was determined by flow cytometry. Percentage of CD26⁺ SC (left) and CD26⁺ progenitor cells (right subpanel) in various categories of the Sokal score (A) and Hasford score (B). In high-risk patients, phenotypically more mature progenitor cells tend to acquire CD26. Sokal scoring: high (>1.2), intermediate (int) (0.8-1.2), and low (<0.8). Hasford scoring: high (>1480), int (781-1480), low (≤780). (C) Correlations between the percentages of CD26⁺ SC and the 3 scoring systems. As shown, no substantial correlation was found.