CrossMab is a type of IgG-like bispecific antibody. It remains the general structure and size of a conventional IgG, so it has similar biophysical properties to IgGs. In CrossMAb, KIH (knobs-into-holes) technology is used to permit the heavy chain heterodimerize. Light chain mispairing is overcome by antibody domain crossovers, entire Fab domain crossover, merely variable domains or constant domains crossover. The crossover can keep the antigen-binding capacity of the parental antibody. Usually, the referred CrossMab is a bispecific, bivalent molecule, 1+1 antigen-binding valency. And using the versatile CrossMab technology, multivalent, bispecific molecules can be generated.