A compound represented by the following general formula (I) or a salt thereof: ** Formula ** where X1 represents CH or N； any one of X2, X3 and X4 represents N, and the others represent CH； any one or two of Y1, Y2, Y3 and Y4 represent C-R4, and the others are the same or different and represent CH or N； R1 represents a 5 to 6 membered, unsaturated, monocyclic, optionally substituted heterocyclic group having 1 to 3 heteroatoms selected from N, S and O, or a 9 to 10 membered heterocyclic, unsaturated group, bicyclic, optionally substituted which has 1 to 3 heteroatoms selected from N, S and O； R2 represents a hydrogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms or an optionally substituted alkenyl group having 2 to 6 carbon atoms； R3 represents a cyano group or -CO-R5； R4 are the same or different and represent a hydrogen atom, a halogen atom, a cyano group, an optionally substituted alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aromatic hydrocarbon group, -N (R6) (R7), -S-R8 or -CO-R9； R5 represents an amino group optionally having a hydroxyl group, or an optionally substituted monoalkylamino or dialkylamino group； R6 and R7 are the same or different and represent a hydrogen atom, an optionally substituted alkyl group having 1 to 6 carbon atoms, a halogenoalkyl group having 1 to 6 carbon atoms, an optionally substituted cycloalkyl group having 3 to 7 carbon atoms, an optionally substituted aralkyl group, an optionally substituted aromatic hydrocarbon group, an optionally substituted saturated heterocyclic group or an optionally substituted unsaturated heterocyclic group, or R6 and R7 optionally form a saturated heterocyclic group, together with the atom of nitrogen to which they are attached； R8 represents an optionally substituted cycloalkyl group having 3 to 7 carbon atoms, or an optionally substituted aromatic hydrocarbon group； and R9 represents a hy
