D) Paclitaxel-only treated HFs showed a significant (adjusted p value = 0.0001 [****]) increase in the number of pH3+ ORS cells following drug washout. Palbociclib treatment alone had no significant effect on the number of pH3+ ORS cells. There was a trending, yet non-significant, increase in the number of pH3+ ORS cells in HFs dual treated with palbociclib plus paclitaxel. Ordinary one-way ANOVA with multiple comparisons performed using N of 9-10 HFs from 3 patients. Values plotted represent the mean total number of cells counted per HF analysed. Error bars are standard error 