A novel amine derivative expressed by general formula (1)
(in the formula: G
1
, G
2
, and G
3
are the same or different and represent CH or a nitrogen atom; R
1
represents a chlorine atom, an optionally-substituted C
3-8
cycloalkyl group, or the like; R
2
represents —COOR
5
(in the formula, R
5
represents a hydrogen atom or a carboxyl protective group), or the like; R
3
represents a hydrogen atom, or the like; and R
4
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.