GPX5 and thyroid cancer: Glutathione peroxidase family showed variable gene expression: GPX1 and GPX2 expression analysis suggested minor increase in mRNA synthesis (Fig. 1j, k), GPX3, GPX5, and GPX7 expression was downregulated in thyroid cancers (Fig. 1l, n, o), whereas GPX4 expression did not change (Fig. 1m).