A novel amine derivative as represented by the general formula (1) or a salt thereof (wherein G1, G2 and G3 are identical or different and are CH or a nitrogen atom； R1 is a chlorine atom, an optionally substituted C3-8 cycloalkyl group or the like； R2 is -COOR5 (wherein R5 is a hydrogen atom or a carboxyl protecting group) or the like； R3 is a hydrogen atom or the like； and R4 is an optionally substituted fused bicyclic hydrocarbon ring group, an optionally substituted bicyclic heterocyclic group or the like) is useful for treatment such as prevention or therapy of the diseases involved in the overproliferation of keratinocytes.一種通式(1)所表示的新穎之胺衍生物或其鹽，(式中，G1、G2以及G3係相同或相異，為CH或氮原子；R1為氯原子或可經取代之C3-8環烷基等；R2為-COOR5(式中，R5為氫原子或羧基保護基)等；R3為氫原子等；R4為可經取代之二環式稠合烴環基或可經取代之二環式雜環基等)，其有用於與角質細胞之過度增殖有關的疾病之預防或治療等之處置。
