NEW AZAINDOLE DERIVATIVE

PROBLEM TO BE SOLVED: To provide a compound effective as an agent for curing, alleviating and preventing cancer diseases, rejection in organ transplants, autoimmune diseases or the like.SOLUTION: The compound represented by formula (I) or its salt is provided, [wherein, -X---X- indicates -NRCO-, -N=CR- or -S-CO-; Rindicates a 1-6C alkyl, an aryl, a heteroaryl, a -CO-saturated aliphatic heterocycle or the like; Rindicates a hydrogen atom, a halogen atom or the like; Rindicates a hydrogen atom or a 1-6C alkyl; Rindicates a hydrogen atom, a 1-6C alkyl or the like; Rand Rindicate each independently a hydrogen atom or a 1-6C alkyl that may be substituted with a fluorine atom; and Y indicates a 1-6C alkylene or the like that may be substituted with one or two 1-6C alkyls].