The specific strengths of the current study are the relatively large number of patients, including a control group of patients under other ALK TKIs; the wide array of examined hematologic parameters, including longitudinal tracking; the precise quantification of various morphologically abnormal erythrocyte subpopulations; the genetic testing using NGS to rule out spherocytosis; and consideration of patient outcomes as well as the molecular features of the disease. The gene discussed is ALK; the disease is hereditary spherocytosis.