Peripheral blood smears in altered volume homeostasis. (Left) Hereditary xerocytosis. (Right) Hereditary hydrocytosis. (Left) A Wright-stained peripheral blood smear from a patient with hereditary xerocytosis due to a PIEZO1 mutation showing rare stomatocytes, occasional dessicytes–dense, abnormal erythrocyte forms where hemoglobin appears puddled at the periphery, and rare target cells. (Right) A Wright-stained peripheral blood smear from a patient with hereditary hydrocytosis is shown. Numerous stomatocytes, erythrocytes with a central mouth-like “stoma” are seen.