In addition, a statistically significant negative correlation was found between the percentage of non-classical monocytes expressing TLR4 and the phototype measurement using a mexameter on the forehead (rho = −0.37, p = 0.024), cheek (rho = −0.35, p = 0.032) and erythema—forehead (rho = −0.41, p = 0.010). This evidence concerns the gene TLR4 and Erythema.