Lectin that binds galactose, galactose-containing sugars and gentiobiose. It is strongly mitogenic for human T-lymphocytes and induces the release of interleukin-1 beta and tumor necrosis factor alpha from cultured mononuclear cells. It has a strong hemagglutininating activity. Homodimer. The production of this lecting varies with seasons being higher in late spring. N-glycosylated. An isoform with Ala-1 missing is found in 20% of the samples.