Various whole cell extracts (30 μg) were separated by 5% SDS-PAGE, and the membrane was blotted with mtRNA polymerase antibody [HL3068] (GTX640514) diluted at 1:1000. The HRP-conjugated anti-rabbit IgG antibody (GTX213110-01) was used to detect the primary antibody. Corresponding RNA expression data for the same cell lines are based on Human Protein Atlas program.