IL6 and neurodegenerative disease: The role of estradiol is not fully understood, but studies have shown that estradiol plays an important role in neurodegenerative diseases in an anti-inflammatory fashion (Marin and Diaz, 2018; Aguirre-Vidal et al., 2017; Sahab-Negah et al., 2020), since estradiol can upregulate the synthesis and secretion of inflammatory factors, e.g., TNFα, CXCL-8, IL-8, and IL-6 (Aguirre-Vidal et al., 2020).