The substantial costs of clinical trials, the lengthy timelines of new drug discovery and development, along the high attrition rates underscore the need for alternative strategies for finding quickly suitable therapeutics agents. Given that most approved drugs possess more than one target tightly linked to other diseases, it encourages promptly testing these drugs in patients. Over the past decades, this has led to considerable attention for drug repurposing, which relies on identifying new uses for approved or investigational drugs outside the scope of the original medical indication. The known safety of approved drugs minimizes the possibility of failure for adverse toxicology, making them attractive de-risked compounds for new applications with potentially lower overall development costs and shorter development timelines. This latter case is an exciting opportunity, specifically in oncology, due to increased resistance towards the current therapies. Indeed, a large body of evidence shows that a wealth of non-cancer drugs has beneficial effects against cancer. Interestingly, 335 drugs are currently being evaluated in different clinical trials for their potential activities against various cancers (Redo database). This review aims to provide an extensive discussion about the anti-cancer activities exerted by antimicrobial agents and presents information about their mechanism(s) of action and stage of development/evaluation.

In vitro T cell activation and differentiation are fundamental techniques in immunological research. Here, we present a protocol for the potent activation of T cells using bactericidal/permeability-increasing protein (BPI)-stimulated murine bone marrow-derived cells (BMDCs). We describe steps for preparing supernatants harvested from BPI-stimulated BMDCs (SN BPI). We then detail procedures for purification of (naive) CD4⁺ T cells from murine spleens and peripheral lymph nodes and their consecutive polyclonal activation in the presence of SN BPI. For complete details on the use and execution of this protocol, please refer to Bülow et al.¹.