Thus, we provide in vitro evidence that the N-terminal TSHZ3 variants identified in CAKUT patients may adversely affect SM cell differentiation in the kidney pelvis and proximal ureter in vivo, as suggested by α-SMA immunohistochemistry on the nephrectomy specimen of a TSHZ3 variant carrier. The gene discussed is ACTA1; the disease is congenital anomaly of kidney and urinary tract.