Fig. 1.

Volcano plots of entities found differently regulated in acne grades versus clear skin conditions. Comparison of relative abundance of entities between non-affected sebum and different acne grades was performed by applying univariate statistical analysis to 1,492 entities found in the 75% of samples belonging to at least one skin condition, namely clear, mild, moderate, and severe acne grades. The log2 of the fold-change values is plotted on the x axis, whereas the −log10 of the t-test P values is plotted on the y axis. The vertical and the horizontal green lines mark the threshold of the fold-change and of the P values with Bonferroni’s correction set at 2 and 0.05, respectively. Annotation of species found differently expressed is provided in the consequent assignment of putative identity. Volcano plots returned 6, 95, and 46 entities expressed at significantly different extent in mild (A), moderate (B), and severe (C) acne grades, respectively, when compared with unaffected sebum.