|Galectin 9 is a secreted lectin that is an endogenous ligand of the immune co-inhibitory receptor, TIM3. Galectins bind β-galactoside sugar modifications on proteins, and have been associated with metastasis and immunosuppression. Galectin 9 contains two tandem carbohydrate recognition domains (CRD) within its peptide structure. The CRDs are homologous but distinct in their primary sequence. The whole peptide sequence provided here is for the longest isoform reported to date. Uniprot records 6 human protein isoforms [2-3]. Isoform 2 is known as ecalectin, and is reported to be a novel eosinophil chemoattractant produced by T lymphocytes [1,4-5,7]. The regulation and function of galectin 9 in physiological and pathological conditions was reviewed by Hirashima et al. (2004) .