ERBB2 and oral cavity squamous cell carcinoma: Anti-neoplastic cytotoxicity of gemcitabine-(C4-amide)-[anti-HER2/neu] would likely have been greater if it had been evaluated using an incubation period greater than 182-hours or had been determined against human promyelocytic leukemia, T-4 lymphoblastoid clones, glioblastoma; cervical epitheliod carcinoma, colon adenocarcinoma, pancreatic adenocarcinoma, pulmonary adenocarcinoma, oral squamous cell carcinoma, or prostatic carcinoma.