Consistent with previous studies showing MELK to be expressed in the stem-cell enriched glioblastoma cells (CD133 positive cancer cells) [9], we found significantly higher MELK expression in the less differentiated leukemic cell population (enriched for CD34+ cells) than in the more differentiated cell population (CD34- cells), implying a possible role of the MELK gene in stem cell maintenance. The gene discussed is PROM1; the disease is cancer.