The present invention relates to a compound of formula (I), wherein X<1>, X<2> and X<3> are, independently of each other, N or CH; with the proviso that at least two of X<1>, X<2> and X<3> are N; Y isN or CH; W is H or F; with the proviso that when W is F, then X<1>, X<2> and X<3> are N; R<1> and R<2> are independently of each other (i) a morpholinyl of formula (II) wherein the arrow denotes thebond in formula (I); and wherein R<3> and R<4> 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(O)0-C1- C2alkyl; or R<3> and R<4> form together a bivalent residue -R<5>R<6>- 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 R<7>; wherein R<7> isindependently at each occurrence C1-C3alkyl optionally substituted with one or two OH, C1-C2fluoroalkyl, C1- C2alkoxyC1-C3alkyl, C3-C6cycloalkyl; or two R<7> substituents form together a bivalent residue -R<8>R<9>- 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 R<1> and R<2> is a morpholinyl of formula II; andprodrugs, 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.