M: gene expression stability. PPIA: cyclophilin A (or peptidylprolyl isomerase A) gene; RPLP0: acidic ribosomal protein gene; GNB2L1: guanine nucleotide-binding protein, β-peptide 2-like 1, gene; PGK1: phosphoglycerokinase gene; GUSB: β-glucuronidase gene; B2M: β₂-microglobulin gene; RNR1: 18S ribosomal RNA gene; GAPDH: glyceraldehyde-3-phosphate dehydrogenase gene; ACTB: β-actin gene; TFRC: transferrin receptor gene. ^#: genes listed from most to least stable for all three methods; ^¶: stability value; ⁺: all 10 candidate HKGs were highly correlated and were combined to calculate the BestKeeper index, which was then used to determine the correlation between each HKG and the index.