Examples of demographic factor correlations with community classes. (A) Gender differences in retroauricular crease samples, with females more prevalent in the Staphylococcus community class. (B) Gender differences in community classes of antecubital fossa. The Propionibacterium community class has significantly more males than females while the non-Propionibacterium community classes have significantly more females than males. (C) The Staphylococcus community class in anterior nares is dominated by females, and the female proportion is significantly higher than in the other three community classes. (D) The ages of subjects in the Propionibacterium community class and the other community classes of retroauricular crease are significantly different. Asterisks indicate statistically significant differences.