The era of biotechnology is about to begin. In particular, there are growing expectations and potential for drug discoveries with the use of the innate immune system. That is because modulation of the innate immune system and maximization of humans’ innate self-healing ability (immune function) may allow patients to overcome refractory disease without adverse reactions. Research and development of galectin-9-based therapeutic agents meet the needs of the age, and we aim to make a social contribution by developing therapeutic agents without adverse reactions.