Thioredoxin reductase 1, cytoplasmic (TXNRD1)

Isoform 1 may have glutaredoxin activity in addition to thioredoxin reductase activity and induces actin and tubulin polymerization, resulting in formation of cell membrane protrusions. Isoform 4 enhances the transcriptional activity of estrogen receptors alpha and beta while isoform 5 enhances the transcriptional activity of the beta receptor only.

Isoform 5 also mediates cell death induced by a mixture of interferon-beta and retinoic acid. .