Finally, we have observed that docosahexaenoic acid (DHA; 22:6), a long-chain ω-3 polyunsaturated fatty acid primarily found in dietary fish oil [26–29], inhibits tumor-associated GrB expression in bladder and pancreatic carcinoma cells while simultaneously suppresses their invasion in vitro, suggesting the involvement of GrB in the inhibition of tumor cell invasion by DHA [25]. The gene discussed is GZMB; the disease is exocrine pancreatic carcinoma.