MMP1 and Uterine leiomyoma: We have previously reported that Cd induces increased cell proliferation of human uterine leiomyoma (fibroid) cells through nongenomic activation of the ERK/MAPK pathway (Gao et al. 2015), and that Cd does not significantly bind to estrogen receptor alpha or beta, nor does it show transactivation in the cells transiently transfected with Estrogen Responsive Element (ERE) luciferase reporters; however, we found Cd-induced activation of GPER1 with mediation of matrix metalloproteinase 1&2 (MMP1&2) and EGFR in vitro (Gao et al. 2015; Liu et al. 2019).