Human CD47 protein expression is heterogeneous, whereas MHC class I expression is homogeneous across TCL. (A) CD47 expression on normal peripheral blood-derived CD3⁺ T cells from healthy donors and TCL lines was determined by flow cytometry. CD47 surface density was plotted after mean fluorescence intensity was normalized for cell size. Each point represents a different healthy donor (n = 10) or TCL line (ALCL = 9 [DL-40, FEPD, KI-JK, L82, MAC2A, Karpas 299, SR-786, SU-DHL-1, SUP-M2], CTCL = 4 [HH, HuT-78, MJ, Myla], NKTCL = 3 [MTA, KHYG-1, SNK6], γδTCL [Karpas 384], HSTCL [DERL-2], PTCL-NOS = 2 [OCI-Ly12, SMZ-1], ATLL = 1 [HuT-102], and NKLGL = 1 [NKL]) or BCL line (Burkitt [Raji, Daudi], DLBCL [SU-DHL-2, SU-DHL-5, and Mantle cell [JVM-2]). **P = .0021 by 2-sided Welch t test. Normalized mean expression for each population was: CD3⁺ T cells 69.85 (range, 47.1-93.5) and TCL lines 176.9 (range, 20.9-694.8). (B) Resting CD3⁺ T cells from 2 additional donors (D#1, D#2) and TCL whole cell lysates were immunoblotted with the indicated antibodies. (C) Differential CD47 expression measured by RNA-seq was batch corrected and plotted. Three healthy donors were used for naïve, effector, and follicular helper T-cell groups. Cell lines: ALK+ ALCL = 3 (KI-JK, L82, SR-786), ALK- ALCL = 3 (MAC2A, OCI-Ly13.2, FEPD), PTCL-NOS = 2 (OCI-Ly12, SMZ-1), CTCL = 3 (HH, HuT-78, Myla), NK/TCL = 2 (KHYG-1, MTA). PDXs: ALK⁺ ALCL = 2 (WCTL-91953, WCTL-81162), AITL = 3 (DFTL-94393, DFTL-78024, DFTL-47880), HSTL = 1 (DFTL-81777), ATLL = 1 (DFTL-69579), T-PLL = 1 (DFTL-28776), and NK/TCL = 1 (DFTL-85005). (D) Representative images of patient lymph nodes stained for H&E, CD47 showing low and high H-scores and for MHC class I. Scale bar: 0.05 mm. (E) Histological analysis of CD47 expression in TCL patient-derived primary samples in the TMA (other: CTCL = 3, ATLL = 5, NK/TCL = 3, T-PLL = 1, subcutaneous panniculitis-like TCL = 2, γ/Δ TCL = 2, TCL unclassifiable = 3, and T-cell lymphoblastic lymphoma = 2). (F) PFS comparison between quartile groups by H-score (log-rank, P = .43). (G) PFS comparison between quartile groups by percent CD47⁺ lymphoma cells (log-rank, P = .38). H&E, hematoxylin and eosin.