TLR4 and cerebral cavernous malformation: As shown in Fig. 2a-c, after 1, 2 and 3 days of treatment with CCM, the mRNA levels of CXCL1 and TLR4 in OECs were drastically increased in a time-dependent manner, and a significant difference was found between the CCM-treated and untreated cells at the corresponding durations.