MMP2 and keratoacanthoma: In patients with keratoacanthoma, the MMP-2 variations were in the range 85–102 RFU/mg protein, with a variance of 6.40%, the median (95.50 RFU/mg protein) was close to the mean level of 94.58 ± 6.05 RFU/mg protein, and the result of the Skewness test (t = −0.256) suggests the homogeneity of the series of values (Table 2).