IHC staining showed an extremely low GPX4 expression in normal tissues and this expression was relatively low in superficial gastritis (SG), mildly upregulated in atrophic gastritis with intestinal metaplasia (AG with IM), moderately increased in dysplasia (DYS), and remarkably upregulated in GC tissues (Fig. 3f–i). This evidence concerns the gene GPX4 and chronic atrophic gastritis.