Myosin IIA contractility and Piezo1 are necessary to initiate ultrasound‐mediated apoptosis in MDA‐MB‐231 cancer cells. (a) F actin‐stained images of wild‐type and constitutively active RhoA transfected cells, scale bar: 100 μm. (b) Annexin‐stained images showing apoptotic cells in control and RhoA transfected cells with and without US treatment. (c) Bar diagram displaying percentage of apoptotic cells in control and RhoA transfected cells upon US treatment, n > 500 cells. (d) Annexin‐stained images showing apoptotic cells in Y27362‐ and blebbistatin‐treated cells with and without US treatment. (e) Bar diagram displaying percentage of apoptotic cells in Y27362‐ and blebbistatin‐treated cells upon US treatment, n > 2500 cells. (f) Annexin‐stained images showing apoptotic cells in control siRNA and Piezo1 KD cells with and without US treatment. (g) Bar diagram displaying percentage of apoptotic cells in control siRNA and Piezo1 KD samples upon US treatment, n > 2000 cells. *p < 0.05, **p < 0.01, ****p < 0.0001. In image panels b, d, and f, scale bar: 75 μm