NAGA and cancer: The main goal of this study was to evaluate in vitro alkaloids aaptamine (1), isoaaptamine (2), 9-demethylaaptamine (3), aaptanone (4), damirones A (5) and B (6), makaluvamines H (7) and G (8), and zyzzyanone A (9) isolated from marine sponges as direct or indirect inhibitors of α-N-acetylgalactosaminidase (α-NaGalase) from human cancer cells.