GSTM1 and hypertensive disorder: Yet, this PEGylated Hb appears not to elicit the hypertensive response typically observed in most other acellular Hbs [17], in agreement with independent observations in a conscious-hamster dorsal-skinfold model that documented lesser vasoconstriction and hypertension upon the infusion of larger HBOCs in the 7–224 nm diameter range [151].