SOAT1 and Erythema: As depicted in Figure 6A–C, the PPD induration/EC erythema groups were compared with the PBS group as regards biological processes, with DEPs mainly associated with functions such as negative regulation of endopeptidase activity, complement activation, acute phase reaction, hemostasis, participation in immune system reaction, positive regulation of tyrosine phosphorylation of signal transducer and activator of transcription (STAT) protein, and inflammatory response.