The percentages of TrkA-positive NP and AF cells in the control and gel groups were nearly unchanged from postoperative day 1 to day 28 (Fig. 4f), and the percentages of TrkA-positive NP and AF cells in the gel group were significantly lower than those in the aspiration group at each time point (aspiration vs. gel, P < 0.01, each time point except for the percentages of NP cells on day 1, NP cells; P = 0.03 on day 1, Fig. 4g,h). The gene discussed is NTRK1; the disease is atrial fibrillation.