Preclinical work shows that fucoidan, a seaweed-derived polysaccharide, boosts CAR‑T cell efficacy against non-Hodgkin lymphoma in laboratory models. The study demonstrates that fucoidan augments CAR‑T expansion and anti-tumor activity when used as a combinatorial adjunct, suggesting a low-toxicity route to improve cellular therapy responses. The data support translational evaluation of dietary or purified fucoidan supplements as adjuncts in CAR‑T manufacturing or treatment protocols.