We had previously demonstrated that siRNA-delta-5-desaturase knockdown in different types of cancer cells can promote the production of 8-hydroxyoctanoic acid from intensified Cyclooxygenase-2-catalyzed dihomo-γ-linolenic acid peroxidation; the 8-hydroxyoctanoic acid served as an HDAC inhibitor to suppress cancer cell growth, migration, and invasion [25–29]. The gene discussed is HDAC9; the disease is cancer.