The histologic and mutational profiles of NK-cell enteropathy (all data from case 2 except panel J from case 3). (A-B) Hematoxylin and eosin histologic pictures. (C-E) Immunohistochemical stains of CD2 (C), cytoplasmic CD3 (D), and CD56 (E). (F) EBER in situ hybridization. (G) Somatic mutations identified by targeted next-generation sequencing panel (MSK heme IMPACT). (H) Snapshot of the Integrative Genomic Viewer window showing an in-frame deletion (K563_C565) in exon 12 of JAK3. The bottom letters show bases and amino acids. (I) Lollipop illustration of JAK3 K563_C565del mutation. (J) Representative graph of droplet digital PCR studies. x-axis, WT allele; y-axis, JAK3 K563_C565del allele. Inset, normal control. (K-L) Immunohistochemical results of anti-p-STAT5 (K), anti-p-STAT3 (L), and anti-p-ERK (L inset) in NK-cell enteropathy.