Although breastfeeding seemed to protect women from relapse, a considerable body of literature covered in an excellent review (274) implicates prolactin as one of the causes of the post-partum surge in MS symptoms, and this phenomenon is similar to higher prolactin levels found in post-pubertal female subjects that plays a role in increasing their susceptibility to Th1-mediated autoimmune diseases (179). Here, PRL is linked to myeloid sarcoma.