Residual blasts maintained their migratory properties after chemotherapy. A, CD11b, CD14, CD15, and CD44 cell-surface expression in viable control or AraC-treated (2 μmol/L) U937 cells for 96 hours (n = 4). B, Gene set enrichment analysis of “HAY_BONE_MARROW_MONOCYTE” gene signature in AraC versus untreated AML samples from three different transcriptomic analyses. C, Number of migrating cells in the presence or absence of CD36-blocking antibody (FA6-152) sorted from control or 2 μmol/L AraC-treated cells for 4 days (normalized to control; n = 3). D, Percentage of viable CD36-low and CD36-high cells in PBS or 2 μmol/L AraC-treated U937 cells for 4 days (n = 4). E, Representative histograms of CD36 expression in nonmigrating versus migrating CD36-low and CD36-high subpopulations sorted from control or AraC-treated U937 cells (2 μmol/L) for 4 days. Plain histogram, nonmigrating cells; striped histogram, migrating cells. F, Quantification of CD36 expression in nonmigrating versus migrating cells in the same conditions as in E (n = 3). G, Number of migrating cells from CD36-low and CD36-high subpopulations sorted from control or 2 μmol/L AraC-treated U937 cells for 4 days (normalized to Ctrl CD36-low cells; n = 3). H and I, Quantification in the BM (H) and spleen (I) of viable U937 cells transduced with shCtrl (n = 9) or shCD36 (n = 9) in mice relapsing after AraC treatment. J–M, Quantification of U937 cells by RT-qPCR (hCD45 mRNA normalized to m36B4) in SCAT (J), PGAT (K), lung (L), and kidneys (M) in mice relapsing after AraC treatment. Data expressed as 2−ΔCT (values multiplied by 1,000; n = 4–5 shCtrl, n = 5–7 shCD36). Values are represented as mean ± SEM. A, Mann–Whitney or unpaired t test depending on sample distribution. B, Unpaired t test. C and G, Ordinary one-way ANOVA with Tukey multiple comparisons test. F, Ordinary two-way ANOVA with multiple comparisons correction. H–M, Unpaired t test with or without Welch correction depending on sample variance. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001; ns, not significant.