A compound for use in a method for (a) treating a ciliopathy in a subject in need thereof, (b) treating a disease or disorder selected from obesity, liver disease, retinal degeneration, olfactory dysfunction, hyperlipedemia, type 2 diabetes, and metabolic syndrome, in a subject suffering from a ciliopathy, or (c) preventing or delaying the onset and/or development of a ciliopathy in a subject diagnosed as being at risk of developing said ciliopathy, wherein the compound is a compound of formula, or a pharmaceutically acceptable salt thereof, wherein: R 1 is selected from hydrogen, halogen (e.g., fluorine), cyano, nitro, hydroxy, thio, amino, C 1-6 -alkyl (e.g., methyl or ethyl), C 2-6 -alkenyl, C 2-6 -alkynyl, C 1-6 -alkyloxy, C 2-6 -alkenyloxy, and C 2-6 -alkynyloxy, wherein said alkyl, alkenyl, alkynyl, alkyloxy, alkenyloxy, or alkynyloxy is optionally substituted with one or more (e.g., 1, 2 or 3) groups selected from halogen, cyano, nitro, hydroxy, thio or amino; R 2 and R 3 are independently selected from C 1-3 -alkyl, optionally substituted by one or more ( e.g. 1, 2 or 3) halogens, or R 2 and R 3 together form a cyclopropyl or cyclobutyl group, optionally substituted by one or more ( e.g. 1 or 2) halogens; R 4, R 5 and R 6 are each independently selected from hydrogen, halogen, nitro, hydroxy, thio, amino, C 1-6 -alkyl, and C 1-6 -alkyloxy, wherein said alkyl or alkyloxy is optionally substituted by one or more ( e.g. 1, 2 or 3) groups selected from halogen, hydroxy, cyano, and C 1-6 -alkyloxy; and A is a 5- or 6-membered aryl or heteroaryl group (e.g., phenyl or thiazolyl), optionally substituted with 1, 2 or 3 groups independently selected from halogen, hydroxy, thio, amino, nitro, C 1-6 alkoxy and C 1-6 alkyl. (a) treating a ciliopathy in a subject in need thereof, (b) treating a disease or disorder selected from obesity, liver disease, retinal degeneration, olfactory dysfunction, hyperlipedemia, type 2 diabetes, and metabolic syndrome, in a subject suffering from a ciliopathy, or (c) preventing or delaying the onset and/or development of a ciliopathy in a subject diagnosed as being at risk of developing said ciliopathy, or a pharmaceutically acceptable salt thereof, wherein: R 1 is selected from hydrogen, halogen (e.g., fluorine), cyano, nitro, hydroxy, thio, amino, C 1-6 -alkyl (e.g., methyl or ethyl), C 2-6 -alkenyl, C 2-6 -alkynyl, C 1-6 -alkyloxy, C 2-6 -alkenyloxy, and C 2-6 -alkynyloxy, wherein said alkyl, alkenyl, alkynyl, alkyloxy, alkenyloxy, or alkynyloxy is optionally substituted with one or more (e.g., 1, 2 or 3) groups selected from halogen, cyano, nitro, hydroxy, thio or amino; R 2 and R 3 are independently selected from C 1-3 -alkyl, optionally substituted by one or more ( e.g. 1, 2 or 3) halogens, or R 2 and R 3 together form a cyclopropyl or cyclobutyl group, optionally substituted by one or more ( e.g. 1 or 2) halogens; R 4, R 5 and R 6 are each independently selected from hydrogen, halogen, nitro, hydroxy, thio, amino, C 1-6 -alkyl, and C 1-6 -alkyloxy, wherein said alkyl or alkyloxy is optionally substituted by one or more ( e.g. 1, 2 or 3) groups selected from halogen, hydroxy, cyano, and C 1-6 -alkyloxy; and R 1 is selected from hydrogen, halogen (e.g., fluorine), cyano, nitro, hydroxy, thio, amino, C 1-6 -alkyl (e.g., methyl or ethyl), C 2-6 -alkenyl, C 2-6 -alkynyl, C 1-6 -alkyloxy, C 2-6 -alkenyloxy, and C 2-6 -alkynyloxy, wherein said alkyl, alkenyl, alkynyl, alkyloxy, alkenyloxy, or alkynyloxy is optionally substituted with one or more (e.g., 1, 2 or 3) groups selected from halogen, cyano, nitro, hydroxy, thio or amino; R 2 and R 3 are independently selected from C 1-3 -alkyl, optionally substituted by one or more ( e.g. 1, 2 or 3) halogens, or R 2 and R 3 together form a cyclopropyl or cyclobutyl group, optionally substituted by one or more ( e.g. 1 or 2) halogens; R 4, R 5 and R 6 are each independently selected from hydrogen, halogen, nitro, hydroxy, thio, amino, C 1-6 -alkyl, and C 1-6 -alkyloxy, wherein said alkyl or alkyloxy is optionally substituted by one or more ( e.g. 1, 2 or 3) groups selected from halogen, hydroxy, cyano, and C 1-6 -alkyloxy; and A is a 5- or 6-membered aryl or heteroaryl group (e.g., phenyl or thiazolyl), optionally substituted with 1, 2 or 3 groups independently selected from halogen, hydroxy, thio, amino, nitro, C 1-6 alkoxy and C 1-6 alkyl.