The top six hub genes were calculated according to MCC, Degree, and MNC algorithms (Figure 7B), and included COL1A1, CX3CL1, LOXL2, GPT, NOX4, and MX1. These genes were the most important genes in the PPI network and may contribute to the pathogenesis of SSc. Here, COL1A1 is linked to systemic sclerosis.