NAGA and duodenal adenocarcinoma: In 2023, a report was published in which the authors determined that a high-molecular-weight fraction of phlorethols with a degree of polymerization (DP) of 11–23 phloroglucinols, isolated from the brown algae Costaria costata, serves as an effective marine-based natural inhibitor of cancer cell–associated immunosuppressive α-N-acetylgalactosaminidase (α-NaGalase), particularly in duodenal adenocarcinoma and melanoma cells.134