To address this, we established an animal model in which inoculation of mouse 4T1 BC and E771 cells in tibiae developed an acidic microenvironment, promoted innervation and sprouting of SNs, and increased excitation of SNs following up-regulation of the expression of the acid-sensing nociceptor TRPV1, leading to the induction of BCIBP. Here, TRPV1 is linked to breast cancer.