TAC1 and disease of the tendon: We found higher expressions of the genes including collagen type 3 α1 (COL3A1), prostagladin endoperoxide synthase 2 (PTGS2 = COX2), scleraxis (SCX), matrix metalloproteinase 1 (MMP1), α-smooth muscle actin (ACTA2), tachykinin precursor 1 (TAC1 = SP), and neurokinin-1 receptor (NK-1R) in cultured cells from the tendinopathy tendon compared to those of the cultured cells from the healthy tendon (p < 0.01, in all).