This invention provides methods for treating diseases or conditions wherein the inhibition of Kit protein kinase may be beneficial, using pharmaceutical or cosmetic compositions comprising N-(4-methoxyphenyl)-1-phenyl-1H-pyrazol-3-amine (FPL-62064) and related compounds. This invention also relates to the treatment of skin disorders, such as hyperpigmentation and cutaneous mastocytosis, and to cosmetic uses such as skin lightening.