The RBC-diff accurately detects physiologic and clinical signals. Comparison of RBC-diff counts across 5 cohorts with expected morphologic differences driven by physiologic shifts or clinical interventions: (A) hereditary spherocytosis and elliptocytosis, (B) before and after liver transplantation, (C), before and after RBC exchange in patients with sickle cell disease, (D) before and after intravenous iron supplementation in patients with iron-deficiency anemia, and (E) before and after splenectomy. RBC-diff counts for all morphologies of the patients in panels A-E are shown in supplemental Figure 4. The test statistics for panels A-E are 16.0, 6.16, 2.39, 3.90, and 2.09, respectively. Black lines reflect interquartile range, white circles represent median, and violin shapes the data distribution.