In addition, current genetic analysis of muscle biopsies in the calvarial periosteum from patients with CM (where the pain was situated) found the expression of pro-inflammatory genes (e.g., CCL8 and toll-like receptor 2) to be significantly increased in patients with CM, attesting to muscle tenderness, whereas the expression of genes that suppress inflammation and immune cell differentiation (e.g., IL-10 receptor subunit alpha and colony-stimulating factor 1 receptor) was decreased [38]. The gene discussed is CCL8; the disease is cutaneous mastocytosis.