TAC1 and endometriosis: Capitalizing on the finding that neuropeptides, such as substance P and calcitonin gene-related peptide (CGRP), secreted by sensory nerves surrounding the endometriotic lesions actively facilitate lesion progression and fibrogenesis (Liu et al., 2019; Yan et al., 2019b), a deep endometriosis mouse model can be established by chronic infusion of substance P and/or CGRP in a conventional endometriosis mouse model.