A cell proliferation inhibitor comprising a compound of the formula or a pharmacologically acceptable salt thereof as an active ingredient: wherein J 1 and J 2 each represent CH or N, with the proviso that J 1 and J 2 are not simultaneously CH; r represents 0 to 4; each R 101 is the same or different when r is 2 or more, and represents a halogen atom, a C 1-6 alkyl group optionally substituted with a halogen atom, OR 111, or a group represented by the formula: -N(R 112a)-R 112b, where R 111, R 112a and R 112b are each independently a hydrogen atom or a C 1- s alkyl group; s represents 0 to 5; each R 102 is the same or different when s is 2 or more, and represents a halogen atom, a C 1-6 alkyl group, OR 113, a group represented by the formula: - N(R 114a)-R 114b a group represented by the formula: -NH-C(=O)-R 115, a group represented by the formula: -C(=O)-R 116, an optionally substituted aryl group, an optionally substituted heteroaryl group, a nitro group, or a cyano group, where R 113 is a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aryl group, an optionally substituted arylalkyl group, or an optionally substituted heteroaryl group, R 114a and R 114b are each independently a hydrogen atom or a C 1-6 alkyl group, R 115 is an optionally substituted alkyl group, an optionally substituted aryl group, an optionally substituted heteroaryl group, or a group represented by the formula: -NH-R 121, R 116 is an optionally substituted alkyl group, an optionally substituted aryl group, an optionally substituted heteroaryl group, OR 122, or a group represented by the formula: -N(R 123a)-R 123b, R 121 is an optionally substituted alkyl group, an optionally substituted aryl group, or an optionally substituted heteroaryl group, R 122 is a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aryl group, or an optionally substituted heteroaryl group, and R 123a and R 123b are each independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aryl group, or an optionally substituted heteroaryl group, or R 123a and R 123b are linked together to form a cyclic amine; R 103 represents a hydrogen atom, a C 1-6 alkyl group, a C 3-6 cycloalkyl group, or a C 3-6 cycloalkyl C 1-6 alkyl group; and R 101 and R 103 are optionally linked together to form a five- to seven-membered ring hetero ring when R 101 is present at the 8-position, wherein the cell proliferation inhibitor is a tankyrase inhibitor and/or a microtubule inhibitor. wherein J 1 and J 2 each represent CH or N, with the proviso that J 1 and J 2 are not simultaneously CH; r represents 0 to 4; each R 101 is the same or different when r is 2 or more, and represents a halogen atom, a C 1-6 alkyl group optionally substituted with a halogen atom, OR 111, or a group represented by the formula: -N(R 112a)-R 112b, where R 111, R 112a and R 112b are each independently a hydrogen atom or a C 1- s alkyl group; s represents 0 to 5; each R 102 is the same or different when s is 2 or more, and represents a halogen atom, a C 1-6 alkyl group, OR 113, a group represented by the formula: - N(R 114a)-R 114b a group represented by the formula: -NH-C(=O)-R 115, a group represented by the formula: -C(=O)-R 116, an optionally substituted aryl group, an optionally substituted heteroaryl group, a nitro group, or a cyano group, where R 113 is a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aryl group, an optionally substituted arylalkyl group, or an optionally substituted heteroaryl group, R 114a and R 114b are each independently a hydrogen atom or a C 1-6 alkyl group, R 115 is an optionally substituted alkyl group, an optionally substituted aryl group, an optionally substituted heteroaryl group, or a group represented by the formula: -NH-R 121, R 116 is an optionally substituted alkyl group, an optionally substituted aryl group, an optionally substituted heteroaryl group, OR 122, or a group represented by the formula: -N(R 123a)-R 123b, R 121 is an optionally substituted alkyl group, an optionally substituted aryl group, or an optionally substituted heteroaryl group, R 122 is a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aryl group, or an optionally substituted heteroaryl group, and R 123a and R 123b are each independently a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aryl group, or an optionally substituted heteroaryl group, or R 123a and R 123b are linked together to form a cyclic amine; R 103 represents a hydrogen atom, a C 1-6 alkyl group, a C 3-6 cycloalkyl group, or a C 3-6 cycloalkyl C 1-6 alkyl group; and R 101 and R 103 are optionally linked together to form a five- to seven-membered ring hetero ring when R 101 is present at the 8-position, wherein the cell proliferation inhibitor is a tankyrase inhibitor and/or a microtubule inhibitor.