Increased HSPG immunoreactivity localizes with TG2 in RRMS lesions. Compared to low basal levels of Heparan Sulfate Proteoglycans (HSPG) in non-MS control brain tissue, its immunoreactivity was significantly increased (Figure 8J) in blood vessels and perivascular tissue after RRMS (Figure 8E,F) compared to the lesions in PMS (Figure 8H,I). Here, CD44 is linked to premenstrual tension.