Figure 1: Fold of MDR1A/B gene expression in A) NRK-52E, B) Non-Rifampin treated LL-CPK1 and C) Rifampin-treated LL-CPK1 cells. Cells were exposed to either medium-only or 20% NL or 20% HL serum for 24 h (Fed), then serum was removed and cells were starved for 24 h (Starved). Two-way analysis of variance followed by Holm-Sidak test was used to assess differences in MDR1A/B mRNA. Groups under the same line are statistically equivalent, $ indicate significant difference from the respective serum-fed cells, and different letters indicate significant difference between different sera.