A novel amine derivative expressed by general formula (1) (in the formula: G1, G2, and G3 are the same or different and represent CH or a nitrogen atom; R1 represents a chlorine atom, an optionally-substituted C3-8 cycloalkyl group, or the like; R2 represents —COOR5 (in the formula, R5 represents a hydrogen atom or a carboxyl protective group), or the like; R3 represents a hydrogen atom, or the like; and R4 represents an optionally-substituted condensed bicyclic hydrocarbon group, an optionally-substituted bicyclic heterocyclic group, or the like), or a salt thereof is useful in procedures such as the treatment or prevention of conditions related to excessive keratinocyte proliferation.