MMP2 and oral cavity squamous cell carcinoma: In a recent in vivo study, Altamura et al. (37), showed that in feline oral squamous cell carcinoma cell lines, MMP-2 and−9 are expressed at gene and protein level, which in turn may suggest a contribution of feline oral squamous cell carcinoma cells to invasiveness, in agreement with studies on human oral squamous cell carcinomas, where MMPs expression may play a relevant role in determining the invasive phenotype of tumor cells (38).