POSTN and breast cancer: Based on the above, we have reported the importance of inhibiting only pathological POSTN but not physiological POSTN (PN4) [6,7,8,13,16,17,18] and, especially, we showed the effect of the antibody for POSTN exon 17 on the inhibition of mice 4T1 breast cancer cells proliferation, migration, invasion and bone destruction [16].