MMP13 and squamous cell carcinoma: In squamous cell carcinoma of the mouse skin, the effect of estrogen in the regulation of MMP‐13 inhibitor treatment was distinct so that older female mice had higher levels of MMP‐13 and lower levels of estradiol resulting in more effective MMP‐13 inhibitor treatment; if ovariectomy was made in young females, or 17β‐estradiol supplemented in older females, the effectiveness of the treatment was compromised (Meides et al., 2014).