SPP1 and ischemic stroke: Investigation of the time course of osteopontin and CD44 receptor expression, and osteopontin-CD44 interaction in peri-infract and infarct core NVU cells, however, revealed the strongest osteopontin and CD44 receptor expression, and osteopontin-CD44 interaction 15 h post-tMCAO (Fig. 1, Supplementary Fig. S1), prompting us to further optimize the anti-OPN antibody therapy by establishing a combined treatment regimen with anti-osteopontin antibody in the early and late acute phase of ischemic stroke.