Differential LDL accumulation can be accurately measured using flow cytometry assays that can also distinguish LDL accumulation increased by mevastatin or DNR in NB4 and KG1a AML cells. (A) Cells were incubated in the dark at 37° C to allow LDL binding and internalization and LDLR recycling, and LDL-bodipy signals were recognized by flow cytometry, after gating to exclude dead cells and nonblasts in analyses of primary AML cell samples, and using 20-fold molar excess unlabeled LDL to distinguish LDLR-specific binding, as more completely described in “Materials and methods.” (B) Untreated cells of AML cell lines showed reproducibly different levels of LDL accumulation, and these were lower than accumulation levels in TAMH liver cells. (C) LDL accumulation was increased in NB4 AML cells by mevastatin (MEV), in a dose-dependent manner (2.5 μM and 6.25μM MEV data shown here), and to a similar degree as anti-LDLR antibody binding was increased. Mean LDL accumulation increments are plotted for panels C and D, and error bars represent SEM. Bold horizontal lines indicate the mean.