Using the Gr1a1Neu allele [55,56] which is a whole-body knockout (KO) allele of GSR, we generated KrasG12D/+; Nrf2+/+; Gsra1Neu/a1Neu (GSR KO) and KrasG12D/+; Nrf2D29H/+; Gsra1Neu/a1Neu (GSR KO) lung tumors to evaluate the requirement of GSR for tumor initiation and progression. Here, GSR is linked to neoplasm.