Animal models in molecular biology research: Challenges, ethical imperatives, and the path to human-relevant...

Experimental animal models have historically been pivotal in molecular biology, providing insights into gene function, disease causes, and therapeutic advancements. However, their translational relevance is increasingly scrutinized due to interspecies variations, ethical dilemmas, and restricted reproducibility. The objective of this study is to critically analyze the obstacles and ethical considerations related to animal models in molecular biology, while highlighting the promise of human-relevant and combinatorial techniques to enhance translational outcomes. A narrative synthesis of literature published from 2013 to 2025 was performed via PubMed, Scopus, Web of Science, and Google Scholar. Research focusing on model development, translational obstacles, ethical implications, and disease-specific applications-encompassing neurodegenerative, metabolic, oncological, hepatic, renal, and pain models-was prioritized. Animal models are indispensable but insufficient for precisely mirroring human disease. Principal challenges include species variability, infrastructural limitations, and insufficient reproducibility. Innovative approaches such as humanized models, organoids, and CRISPR/Cas9 technologies, when combined with rigorous methodologies, controlled heterogeneity, and ethical safeguards, offer a means to improve the predictability and reliability of preclinical research. Progress in molecular biology needs to include strict planning, long-lasting infrastructure, and new ideas from interdisciplinary fields. Integrating human-relevant and combinatorial approaches can improve the scientific integrity and ethical underpinning of biomedical research.