The authors found that: (1) PTH behaviors and the responsiveness to anti-CGRP monoclonal antibody treatment is different between the sexes; (2) female rats displayed a prolonged period of cephalic hyperalgesia (i.e., increased sensitivity to pain in the head); (3) increased responsiveness to a headache trigger; and, (4) a poorer effectiveness of an early and prolonged anti-CGRP treatment (44). Here, CALCA is linked to Headache.