Agents that inhibit the dimerization of a prototypic galectin such as galectin-7 are described. These agents, for example antibodies and peptides, bind to a domain corresponding to residues 13-25, 86-108 and/or 129-135 of human galectin-7. The use of such agents to inhibit a biological, physiological and/or pathological process that involves prototypic galectin dimerization, for example for the inhibition of galectin-7-mediated apoptosis and the treatment of galectin-7-expressing cancers, is also described.