PPP, fluvastatin or PD166866 do not inhibit 2D proliferation of JB6 P+ cells. Histograms of JB6 P+ cells stained with Cell Proliferation Dye eFluor™ 450 were treated with (A) PPP, (B) fluvastatin, PD166866 (C) or the vehicle, DMSO. Inhibition of proliferation is indicated by higher fluorescent signal that is represented by visually distinct rightward shifted histograms as shown following treatment with mitomycin C (MmC) and cycloheximide (CHX). The same histograms for DMSO, MmC (1.0 µM), and CHX (10 µg/mL) are shown for comparison with PPP, fluvastatin, and PD166866. (D) The eFluor™ 450 MFI of JB6 P+ cells (singlet, SYTOX Red negative cells) stained with Cell Proliferation eFluor™ 450 and treated with PPP, fluvastatin, or PD166866 was graphically depicted. PPP, fluvastatin, and PD166866 did not significantly influence the eFluor™ 450 MFI compared to vehicle (DMSO) controls, whereas MMC and CHX (positive controls) had significantly higher eFluor™ 450 MFI values. (E) PPP, fluvastatin, or PD166866 did not significantly decrease the % of live cells (singlet, SYTOX Red negative cells). MmC and CHX significantly induced cell death at 0.1 and 1.0 µM and 10 and 50 µg/mL respectively. Each treatment group had two replicates and analyzed by one-way ANOVA with multiple comparisons (**p < 0.01; ***p < 0.001).