NAGA and cancer: Some aaptamines and makaluvamines isolated from marine sponges showed no direct inhibitory effect on cancer-associated α-NaGalase; however, isoaaptamine, 9-demethylaaptamine, damirone B, and makaluvamine H reduced the expression of the enzyme in the human colorectal adenocarcinoma cell line DLD-1 at a concentration 5 μM [21].