Best combination of reference genes for each group of sample.

aBest trio combination is based in a visual inspection of all the ranks generated by the four software.*Best combination of two genes determined considering the intragroup and intergroup variation. CC: central cuff (injured supraspinatus tendon) samples of cases; PC: posterior superior cuff samples of cases; AC: anterior cuff samples of cases; CCC: central cuff samples of controls; ACC: anterior cuff samples of controls; Bold letters: best pairs of reference genes by more than one software.Best combination of reference genes for each group of sample.