The present invention relates to a compound of formula (I), wherein X1, X2 and X3 are, independently of each other, N or CH； with the proviso that at least two of X1X2 and X3 are N； Y is N or CH； W is H or F； with the proviso that when W is F, then X1, X2 and X3 are N； R1 and R2 are independently of each other (i) a morpholinyl of formula (II) wherein the arrow denotes the bond in formula (I)； and wherein R3 and R4 are independently of each other H, C1-C3alkyl optionally substituted with one or two OH, C1-C2fluoroalkyl, C1-C2alkoxy, C1-C2alkoxyC1-C3alkyl, CN, or C(0)0-C1- C2alkyl； or R3 and R4 form together a bivalent residue -R5R6- selected from C1-C3alkylene optionally substituted with 1 to 4 F, -CH2-0-CH2-, -CH2-NH-CH2-, or any of the structures wherein the arrows denote the bonds in formula (II)； or (ii) a saturated 6-membered heterocyclic ring Z selected from thiomorpholinyl and piperazinyl, optionally substituted by 1 to 3 R7； wherein R7 is independently at each occurrence C1-C3alkyl optionally substituted with one or two OH, C1-C2fluoroalkyl, C1- C2alkoxyC1-C3alkyl, C3-C6cycloalkyl； or two R7 substituents form together a bivalent residue -R8R9- selected from C1-C3alkylene optionally substituted with 1 to 4 F, -CH2-0-CH2- or -0- CH2CH2-0-； with the proviso that at least one of R1 and R2 is a morpholinyl of formula II； and prodrugs, metabolites, tautomers, solvates and pharmaceutically acceptable salts thereof, for use in a method of treating a skin disorder in a subject, wherein said skin disorder is a genodermatosis, a vascular anomaly or a skin disorder selected from scleroderma, sclerodermatous chronic graft-versus-host disease, lichen sclerosus, lichen planus, lichen ruber planus and scars.La présente invention concerne un composé de formule (I), dans laquelle X1, X2 et X3 représentent, indépendamment les uns des autres, N ou CH ； sous réserve qu'au moins deux éléments parmi X1, X2 et X3 représentent N ； Y représente N ou CH ； W représente H ou F ； sous ré
