A Bird's Eye View: A Close Look into Avian CAM Models for Translational Blood Cancer Research.

The chorioallantoic membrane (CAM) is a well-vascularised extra-embryonic membrane that supports avian embryonic development and can be used as an implantation site for xenograft models of various cancers. CAM tumour research models are powerful and versatile, offering a rapid, cost-effective and ethical complement to mouse xenograft studies. Their capacity for real-time observation of tumour growth, angiogenesis and metastasis within an immunocompetent living organism is particularly compelling. While CAM models have been extensively utilised for investigating solid cancers, such as breast, lung and pancreatic, their potential for haematological malignancy research remains comparatively underexplored. This review examines the relevance, advantages and translational potential of avian CAM models in studying blood cancers. Their applications across three primary categories are discussed-leukaemias, lymphomas and myelomas-highlighting experimental approaches that replicate aspects of human disease progression and therapeutic responsiveness. Moreover, the review evaluates species-specific considerations relevant to model fidelity, including evolutionary distance and functional parallels between avian and human haematopoiesis. These comparisons underscore both the opportunities and limitations for utilising CAM models in haematologic malignancy research. For their potential to investigate mechanisms of cancer development and treatment in simple but immunocompetent in vivo settings, we propose that CAM tumour models offer high value as a bridge between in vitro and mammalian in vivo studies for haematology translational research.