Cancer is rooted in genetic background, with the expression of oncogenesis playing a pivotal role in the early stages of tumor formation. Acquired mutations in somatic cells primarily contribute to the development of most common cancers, while specific germline mutations are responsible for rare hereditary cancer syndromes. Within the realm of cancer-associated genes, oncogenes undergo activation, exhibiting phenotypic dominance, whereas tumor suppressor genes experience inactivation, displaying phenotypic recessiveness. The ongoing effort to improve our knowledge about molecular mechanisms involves defining pathways influencing cancer therapy. Technological advancements have made it possible to identify genes integral to cancer development and have significantly contributed to the growing success of precision medicine in oncology, with targeted therapies directed against tumors and components of the tumor microenvironment. This Special Issue, titled “Molecular Biology of Cancer—Implications for Diagnosis and Treatment”, comprises a total of eight contributions. These include five original articles and three reviews, offering fresh insights into cancer biology, molecular genetics, and innovative therapeutic approaches
