Growth inhibition and apoptosis by an active component of OK-432, a streptococcal agent, via Toll-like receptor 4 in human head and neck cancer cell lines - Tano, T; Okamoto, M; Kan, S; Nakashiro, K; Shimodaira, S; Yamashita, N; Kawakami, Y; Hamakawa, H (Oral Oncol, 2012)