Whole cell extract (30 μg) was separated by 5% SDS-PAGE, and the membrane was blotted with P Glycoprotein antibody [C219] (GTX23364) diluted at 1:500. The HRP-conjugated anti-mouse IgG antibody (GTX213111-01) was used to detect the primary antibody, and the signal was developed with Trident ECL plus-Enhanced.