SLCO1B3 and neoplasm: Accordingly, the apparent tumor/normal expression ratio (the T/N ratio) of Ct-OATP1B3 mRNA in each tissue pair was very high (Additional file 1: Figure S1A), even though the exact T/N ratios could not be calculated due to the quantitatively undetectable Ct-OATP1B3 mRNA levels in most normal tissues.