A novel amine derivative ex pressed by general formula (1) (in the formula: G 1, G 2, and G are the same or different and represent C H or a nitrogen atom R represents a cnlorine atom, an optionally-substituted C - cycloalkyl group, or the like R 2 represents -COOR 5 (in the formula, R 5 represents a hydro gen atom or a carboxyl protective group), or the like R 3 represents a hydrogen atom, or the like and R 4 represents an optionally-substi tuted condensed bicyclic hydrocarbon group, an optionally- substituted bicyclic heterocyclic group, or the l ik e , or a salt thereof i s useful in procedures such as the treatment or prevention o f conditions related t o excessive keratinocyte proliferation.