Iron is an essential cofactor. but it is also toxic at high levels. In Schizosaccharomyces pombe. the sensor glutaredoxin Grx4 guides the activity of the repressors Php4 and Fep1 to mediate a complex transcriptional response to iron deprivation: activation of Php4 and inactivation of Fep1 leads to inhibition of iron usage/storage. https://www.diegojavierfares.com/limited-save-Ashwagandha-Extract-60Veggie-Caps-top-grab/