ACE2 and hydrops fetalis: A semi-quantitative assessment of ACE2 immunostaining in non-cardiomyocytes revealed that high levels of ACE2 protein expression were typically detected in the control group, in more than two-thirds of the subjects, as shown in Figure 1B. Conversely, moderate ACE2 immunostaining score was predominantly observed in the stage A and stage B HF groups (in more than three-quarters of the patients).