['To investigate the influence of fibronectin (FN) on cytotoxicity and adhesion of tumor-infiltrating lymphocytes (TIL) from oral squamous cell carcinoma (OSCC).', 'TIL cells were isolated from surgical specimens of 9 patients with OSCC. Specific cytotoxicity for autologous tumor cells were tested by 3H-TdR 4 hours release, and specific TNF-alpha release was detected using enzyme-linked immunosorbent assay. Expression of intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1) on TIL cells were analyzed on FACScan following incubation with FITC-conjugated antibody. Cell adhesion ability was evaluated through detection by optical density (OD) values of bound cells and unbound cells.', 'TIL-specific cytotoxic activity for autologous tumor was significantly enhanced, ranging from 17.7% to 67.6% by incubation on FN (P < 0.005). Cell adhesion was increased ranging from 42.5% to 62.7% by coculturing with FN (P < 0.005). The interaction of TIL with FN increased expression of ICAM-1 and LFA-1 on TIL cells as well. But specific TNF-alpha release was not obviously changed by FN (P > 0.5).'] Does interaction of tumor-infiltrating lymphocyte from oral squamous cell carcinoma with FN enhance its adhesion and cytotoxicity?