TAC1 and hydrops fetalis: Bradykinin and Substance P buildup in patients on ACE‐I/ARB for more than 5 years have recently been reported to be associated with lung cancer.35 With an equal or greater role for neprilysin in bradykinin metabolism than ACE,36, 37 a faster substance P buildup in the lungs appears likely with a sacubitril/valsartan combination, since sacubitril also inhibits ACE.38 The potential for its association with lung cancer appears real, particularly in smokers and patients with COPD, which is present in 16.5%‐22.2% of HF patients.5