Firstly, baseline characteristics of ICH patients were screened using simple linear regression, showing that nine candidate variables (p < 0.1) being associated with PHE volumes, which included sex, current smoking, Glasgow Coma score, NIHSS score, blood glucose, activated partial prothrombin time, hematoma volumes, white blood cells and the baseline levels of serum occludin. This evidence concerns the gene OCLN and hematoma.