MMP2 and keratoacanthoma: The mean MMP-2 level was significantly lower in the control group (epidermis witness) compared to the mean MMP-2 level in both actinic keratosis lesions (12.70 vs. 124.46 RFU/mg protein; p = 0.001), keratoacanthoma (12.70 vs. 94.58 RFU/mg protein; p = 0.001) or Bowen’s disease lesions (12.40 vs. 76.0 RFU/mg protein; p = 0.001) (Table 2, Figure 1).