SDHAF4 and adrenal gland pheochromocytoma: To test this, we developed duplicate SDHAF4KO clones (SDHAF4KO36 and SDHAF4KO81) in a human adrenal pheochromocytoma cell line (hPheo136) and we re-expressed SDHAF4 in SDHAF4KO36 cells (SDHAF4rec; see Supplementary Fig. 2a–h for characterization of the cell lines).