Biotherapy Institute of Japan, Inc. (BIJ) is a Tokyo-based biotechnology company established in 2004, specializing in immunotherapy and regenerative medicine. With certified cell processing facilities in Tsukuba and extensive expertise in immune cell research, BIJ supports the development of cell-based therapies, including NK, and dendritic cells. A flagship innovation from BIJ is BINKIT®, a feeder-free NK cell expansion kit designed to generate high-purity, cytotoxic NK cells from peripheral blood mononuclear cells (PBMCs). Capable of expanding NK cells by 100- to 1,000-fold within two to three weeks, BINKIT® provides a complete culture system—including pre-coated flasks, media, and cytokine cocktails—supporting simplified, scalable workflows without the need for feeder cells. It is widely used in cancer immunotherapy research, combination therapy studies, and other preclinical applications requiring potent NK effector cells.