PBMC-OCs enhanced growth of RPMI8226 cells after exposure to DOX. RPMI8226 cells were exposed to 0, 0.2, and 2.0 μM DOX for 2 hours and washed, followed by plating out at 2 × 10⁵/mL in alpha-MEM containing 10% FBS in quadruplicate into 24-well culture plates in the presence (▪) or absence (□) of PBMC-OCs (1 × 10⁴/mL). Viable cell number was counted by trypan blue staining at day 4. Data are expressed as means ± SD. *Significantly different by one-way ANOVA with Scheffe post hoc tests, P < .05.