QPCTL (glutaminyl-peptide cyclotransferase like) is an enzyme that catalyzes the cyclization of N-terminal glutamine or glutamate residues to pyroglutamate (pGlu) in various proteins 1. A primary function of QPCTL involves post-translational modification of CD47, a cell surface protein that serves as a 'don't eat me' signal to macrophages 2. QPCTL modifies the N-terminus of CD47, which is crucial for CD47's interaction with signal regulatory protein alpha (SIRPα) and subsequent regulation of phagocytosis by immune cells 13. Additionally, QPCTL processes other proteins including chemokines CCL2, CCL7, and CX3CL1, influencing tumor microenvironment and inflammatory responses 1. In cancer contexts, QPCTL expression correlates with disease progression and poor prognosis, particularly in glioma where higher expression is associated with advanced tumor stages and shorter overall survival 3. Senescent cells upregulate QPCTL expression alongside CD47, which suppresses macrophage-mediated removal of both senescent cells and nearby apoptotic debris 2. QPCTL represents an emerging therapeutic target for cancer immunotherapy, as it regulates immune checkpoint proteins and could potentially overcome resistance mechanisms while avoiding side effects associated with direct CD47 targeting 34.