(A to D) SNB19 cells were preincubated in the presence of (A) DMSO vehicle, (B) 10 mM NH4Cl as a positive control for inhibition of acidification, (C) 5 μM clomiphene, or (D) 0.8 μM toremifene for 1 hour at 37°C. At this time, Lyso-Tracker Red (± inhibitor, as indicated) was added, and the cells were incubated for an additional 30 min at 37°C. At this time, the cells were fixed, viewed, and photographed with a confocal microscope. Images are representative of 10 fields observed per condition.