Besides, the promoting effects of SY and HSYA on the expression of Nrf2 and antioxidant enzymes have also been reported in pheochromocytoma cells, HepG2 cells, and cardiomyocytes (Wang et al., 2009; Liu et al., 2012; Ma et al., 2016). Here, NFE2L2 is linked to pheochromocytoma.