Biederman et al. [13] also examined kidney biopsies and found ACTB and YWHAZ to be the most suitable RGs, with less favorable results for GAPDH and beta2-microglobulin, acidic ribosomal protein 36B4, and cyclophilin A. While both studies examined a large pool of samples, they were limited by the nature of qPCR compared to RNA-seq, e.g., having to check each RG individually instead of having access to all sequenced transcripts and the lack of available sequencing data from different renal diseases, which were not available at time. This evidence concerns the gene PPIA and kidney disorder.