[Ca2+]i oscillation evoked by CTS stimulation at different strain magnitudes of (a) 3%, (b) 8%, (c) 13%, or (d) 18% in control siRNA-treated chondrocytes (control), TRPV4-KD cells (TRPV4-KD), Piezo1-KD cells (Piezo1-KD), and Piezo2-KD cells (Piezo2-KD). TRPV4: transient receptor potential vanilloid 4; CTS: cyclic tensile strains; KD: knockdown. (A color version of this figure is available in the online journal.)