GSK3B and cancer: At MERCs, p53 reduces the cytosolic oxidation ofSERCA and thus makes SERCA more active (Giorgi et al., 2015).Several additional redox-sensitive MERC proteins are recognized asoncogenic proteins, including proteins mediating the GSK3β pathwaysand frequently undergo oxidation in a cancer context (Koundouros andPoulogiannis, 2018; Zhang et al., 2020).While there is some evidence that MERCs are disrupted in a cancercontext, thus promoting a Warburg metabolic signature with increasedglycolysis (Herrera-Cruz and Simmen, 2017), MERC formation can alsoact as cancer-promoting.