ACOX3 and hypothyroidism: The number of single ACOX1-positive peroxisomes closely adjacent to MTH/LB was expectedly lower, and increase in number of ACOX1-positive peroxisomes (both single ACOX1 and double ACOX1/ACOX3-positive peroxisomes) was noticeable only on day 7 of hypothyroidism (figures 3b1, b2 and 4a).