Clinical phenotype of STK4-deficient patients. (A) H&E-stained bone marrow biopsy shows mild increase in cellularity and full maturation of neutrophil granulocytes. (B) The photograph shows disseminated warts infections in P2. (C) H&E-stained sections from wart biopsy shows orthokeratotic verrucosis and epithelial hyperplasia (P2; original magnification ×100). (D) Echocardiogram (P1) showing atrial septal defect type II (arrow) and left-right shunt. RA indicates right atrium; LA, left atrium; RV, right ventricle; and LV, left ventricle. (E) Giemsa staining of the enlarged inguinal lymph node of P3, showing accumulation of plasmacytoid differentiated cells (original magnification ×400).