 Some research has shown that S1P1 and CD69 co-regulate so that when CD69 is in greater abundance, it results in the removal of S1P1 from the membrane as mentioned above.However, if S1P1 is more abundant than CD69, as would be the case in mature T cells, CD69 membrane localization is reduced.In this manner, regulation of CD69 and S1P1 expression and localization jointly impact lymphocyte egress and migration.