The present invention provides a heterocyclic compound represented by General Formula (1): wherein R1 is a group R5-Z1-, etc., Z1 is a lower alkylene group, etc., and R5 is a group represented by General Formula； wherein R13 is a hydrogen atom, etc., m is an integer from 1 to 5； R2 is a hydrogen atom: Y is CH or N: A1 is a heterocyclic ring selected from the group consisting of indolediyl groups, wherein the heterocyclic ring may have at least one substituent: T is a group -CO-, etc.: R3 is a hydrogen atom, etc.: R4 is a lower alkyl group optionally substituted by one or more hydroxy groups, etc.: R3 and R4, together with the nitrogen atom to which they bind, may bind to each other and form a 5- to 10-membered saturated heterocyclic ring, wherein the heterocyclic ring may have at least one substituent. The heterocyclic compound of the present invention has excellent effects of suppressing the production of collagen and/or treating tumors.
