KEAP1 and neoplasm: To investigate the effect of deletion of all Keap1 or Keap1α alone on tumour growth, Keap1−/− and Keap1β(Keap1Δ1–31), along with Keap1+/+ (wild-type, WT), cell lines were heterotransplanted into three groups of immunodeficient nude mice at their subcutaneous loci as indicated.