Multiple myeloma (MM) is a plasma cell disorder and the second most common blood cancer. While it is still considered incurable, significant progress has been made in understanding its pathophysiological mechanisms, leading to the development of successful therapeutics such as proteasome inhibitors, immunomodulatory drugs, monoclonal antibodies, CAR-T cells, and bispecific antibodies. This special issue aims to highlight recent developments in understanding the molecular complexity of MM, identifying new therapeutic targets, and predictive biomarkers to guide treatment decisions. The articles cover topics such as clinical proteomics, ERBB2 as a predictor of poor survival outcomes, miRNA expression patterns, platelets' role in bleeding and thrombosis, genetic abnormalities in extramedullary MM, machine learning approaches for personalized treatments, autophagy-related gene polymorphisms, and the interaction between macrophages and the urokinase plasminogen activator receptor system in MM. [Extracted from the article]