ELN and aortic aneurysm: This is in agreement with our previous observations, where no differences were observed in volumetric densities of elastin in aortic samples from younger (3-, 6-, and 9-month old) CTRL and MFS mice, suggesting this to be an unsatisfactory parameter for assessing the changes associated with the progression of aortic aneurysm in MFS mice10, and thus, an ineffective measure for assessing the potential beneficial effects of doxycycline treatment.