Researchers at F. Hoffmann-La Roche Ltd. and Hoffmann-La Roche Inc. have described bicyclic tetrahydrothiazepine derivatives acting as diacylglycerol kinase α (DGK-α, DGKA) and/or diacylglycerol kinase ζ (DGK-ζ, DGKZ) inhibitors reported to be useful for the treatment of cancer.