The regulation of T cell trafficking by Camerer et al. [135] S1PR1 has been targeted successfully for the treatment of multiple sclerosis and is being investigated for potential treatment of a number of diseases and use in other clinical contexts, including but not limited to psoriasis, polymyositis, systemic lupus erythematosus, transplantation and oncology [136,137]. This evidence concerns the gene S1PR1 and psoriasis.