Dr. Abdel-Rahim A. Hamad is an Associate Professor of Pathology and Medicine at Johns Hopkins University School of Medicine, where he leads research on unconventional immune lymphocytes. He holds B.V.Sc. and M.V.Sc. degrees in veterinary medicine from the University of Khartoum, Sudan, and a Ph.D. in immunology from the University of Colorado Health Sciences Center. Dr. Hamad’s pioneering research focuses on dual-expressing (DE) cells, also known as “X cells,” a unique lymphocyte population that co-expresses both T cell receptors (TCR) and B cell receptors (BCR). His lab’s discovery of X cells challenged the long-standing paradigm that adaptive immune cells are exclusively T or B cells. Subsequent research has revealed that DE cells express families of antibodies and T cell receptors with germline-encoded antigen-binding sites. Notably, one BCR clonotype within DE cells encodes a potent autoantigen, implicating X cells in the pathogenesis of type 1 diabetes (T1D) and potentially other autoimmune diseases through the cross-activation of self-reactive T cells. Dr. Hamad’s work on X cells has significantly advanced our understanding of T1D, fueling ongoing scientific discussion and debate that highlights the complexity of the field. Supported by Johns Hopkins University and amplified through online platforms, his research positions DE cells as promising therapeutic targets, driving the evolution of both public and scientific discourse.