Involvement of EFhd1 in survival and redox regulated pathways. EFhd1 has been described as a survival factor for neuronal cells and been proposed to mediate muscle cell survival. In response to oxidative stress that can be blocked by superoxide dismutase 2 (SOD2), HNF-4α (hepatocyte nuclear factor 4α) becomes activated. EFhd1 is a direct target of HNF-4α and its expression is repressed by SOD2. Thus, EFhd1 may be involved in a protective cellular response against oxidative stress and, thereby, exhibit anti-apoptotic functions in diverse cell types. Early B cell factor 1 (Ebf1) positively regulates EFhd1 expression in early B cells whereas Suz12 as part of the polycomb repressor complex 2 (PRC2) is a negative regulator of EFhd1 expression.