Further, stimulation of AF cells with TNFα led to a significantly increased expression of MMP3 (p = 0.0006), MMP13 (p = 0.0136), and interleukin 1β (IL1β, p =0.0152) after 24 h compared to the unstimulated starting point (0 h). The gene discussed is MMP3; the disease is atrial fibrillation.