CD44 and cancer: Our lipid conjugates have three major compartments: (1) lipid moiety for anchoring into NK cell membranes via hydrophobic interactions, (2) poly(ethylene glycol) (PEG) acting as an intracellular penetration blocker, and (3) hyaluronic acid (HA) for targeting CD44 overexpressed on aggressive cancer cells (especially triple-negative breast cancer cells) (Scheme 1A).