Sequencing and flow cytometry results of the patient 1 with STAT5b Y665F mutation. (A) The majority of the cells in the CD45-positive lymphocyte population were CD3 and CD8 positive. (B) Gated from CD3⁺ cells, CD8⁺ cells also expressed CD57 antigen and (C) TCR α-β on the cell surface. (D) IGV visualization of exon 16 of the STAT5b gene sequence. The tracks of both CD8⁺ tumor DNA and CD4⁺ control DNA are shown. In the CD8⁺ DNA, 30 of 73 (41%) of the reads supported the variant allele (green), and 43 of 73 (59%) the normal allele (red). In the CD4⁺ DNA, only the normal allele is seen (gray). (E) The mutation T>A (Y665F) in capillary sequencing of CD8⁺ DNA. (F) Ninety-one percent of the CD8-positive cells consisted of a single Vβ21 clone when analyzed by flow cytometry. (G) Only the normal allele T is visible in the capillary sequencing of CD4⁺ DNA. (H) The Vβ analysis of CD4⁺ cells presents normal polyclonal lymphocyte population. Y, tyrosine; F, phenylalanine; PE, phycoerythrin; FITC, fluorescein isothiocyanate; PE-Cy7, phycoerythrin-cyanine 7; T, thymidine; A, adenosine; IGV, Integrative Genomics viewer.