Although AQP4 expression and coverage were substantially reduced at the peri-hematoma region in both control and FKO brains at days 2 and 7 after ICH, no significant difference was observed between genotypes (Figures S6G-S6I), suggesting a minimal role of Col1α1+ fibroblasts in astrocyte polarity after ICH. Here, COL1A1 is linked to hematoma.