CCRL2 and autoimmune disease: Furthermore, four hub genes (degree of interaction > 10) were identified: Sykb, Ccrl2, Sell, and Trem3. We focused on the yellow module, specifically, Sykb because it has emerged as a therapeutic target in autoimmune diseases (38), and we observed an increased expression of SYK mRNA in perilesional skin of BP patients (Figure 1C).