We report here that human T cell chemotaxis, early calcium signaling and MART-1aa26–35*A27L specific CD8+ T cell mediated cytotoxicity are uncompromised in the absence of arginine while interferon-gamma (IFN-γ) and granzyme B secretion are suppressed when tumor antigen specific T cells were restimulated with the cognate peptide under arginine-limiting conditions. The gene discussed is GZMB; the disease is neoplasm.