CTSZ and osteoporosis: However, there was no significant difference in cathepsin Z mRNA levels between osteopenia and osteoporosis patients who were also suffering from chronic inflammatory disorders and those that were not, either when all osteopenia/osteoporosis patients (Supplementary Fig. S1a) or only female osteopenia/osteoporosis patients over the age of 50 (Supplementary Fig. S1b) were included (all osteopenia and osteoporosis patients, 95% CI = −0.180 to 0.134, P = 0.774; female osteopenia and osteoporosis patients over the age of 50, 95% CI = −0.244 to 0.157, P = 0.666, Student’s t-test).