Furthermore, compared to air urethane controls, in the urethane-induced lung cancer model, in utero exposures to SHS significantly increased the volume of the tumors, as well as the number of intrapulmonary metastases, and up-regulated Mmp12 (9.3-fold) in 58-week-old female mouse offspring (Figures 8–13). Here, MMP12 is linked to lung cancer.