Cluster of Differentiation 47 (CD47), an innate immune checkpoint, facilitates immune escape by binding signal regulatory protein alpha (SIRPα) to inhibit macrophage phagocytosis. Its significance in colorectal cancer (CRC) has garnered heightened interest. This review summarizes five immunohistochemistry (IHC) studies and complementary transcriptomic analyses assessing CD47 in CRC. IHC results consistently indicated membrane overexpression, though positivity rates varied widely (16–91%) due to methodological heterogeneity. Transcriptomic results confirmed CD47 upregulation, especially in Consensus Molecular Subtype 1 (CMS1) and CMS4 subtypes and revealed co-expression with immune checkpoints and oncogenic pathways. Clinically, high CD47 levels were associated with advanced TNM stage, metastasis, poor differentiation, and altered immune infiltration; however, the prognostic significance varied among cohorts. Overall, CD47 appears to be a promising biomarker and therapeutic target, but clinical translation requires standardized evaluation, including harmonized antibody selection and scoring cut-offs, and prospective validation.
In colorectal cancer (CRC), tumor progression is influenced by immunosuppressive tumor microenvironment (TME), in which innate immunity and adaptive immunity play an important role. CD47 is one of the key molecules in the process. It sends a “don’t eat me” signal to macrophages by binding to signal regulatory protein alpha (SIRPα), thus helping tumor cells escape immune clearance. Forkhead box P3 (FOXP3)+ regulatory immune cells further suppress antitumor T-cell responses. Here, based on a review of the literature and publicly available transcriptomic data, we propose that CD47 expression and FOXP3+ regulatory T cells in CRC are interconnected components of a broader myeloid–regulatory immunosuppressive phenotype, rather than a simple linear CD47–FOXP3 pathway. Evidence from cancer studies and exploratory GEPIA3/TIMER3.0 analyses supports a weak and method-dependent association between CD47 expression, FOXP3 transcripts, and estimated Treg infiltration. Hippo/Yes-associated protein/transcriptional coactivator with PDZ-binding motif (YAP/TAZ) signaling serves as a potential upstream program contributing to this immune context.