CX3CL1 and Rett syndrome: Furthermore, hNGFp rescued the expression levels of important molecules involved in neuroimmune communication, such as fractalkine (also known as CX3CL1).28 Conclusively, our work supports the broad neuroprotective actions of hNGFp and the use of the nasally-delivered neurotrophin-derivative hNGFp as a prospective therapy for Rett syndrome.