Apoptosis is a crucial process to maintain the correct balance between healthy cells and committed-to-death cells in every tissue. The internal (or mitochondrial) and external (or death receptor) pathways are responsible for driving a series of molecular events that lead to apoptosis by releasing pro-apoptotic proteins, such as B-cell lymphoma-2 (BCL-2) homology 3 (BH3)-only proteins and second mitochondria-derived activator of caspases/diablo inhibitor of apoptosis protein-binding mitochondrial protein (SMAC/DIABLO), that in turn activate the caspase family of proteases. By counterbalancing the apoptogenic machinery, anti-apoptotic BCL-2 family members turn off pro-apoptotic signalling, favouring cell survival, a circumstance that is particularly pronounced in tumour cells in which apoptosis is deranged. Therefore, targeting the defective apoptotic process has become a viable therapeutic option for the treatment of several cancers and much effort is being made in the research and development of effective compounds. This review discussed and updated the most promising therapeutic strategies that target deranged apoptosis process in cancer by mimicking the pro-apoptotic effects of BH3-only and SMAC/DIABLO proteins.

3₁₀-Helices represent the third most abundant secondary structure proteins. Although understandably overshadowed by α-helices for decades, the 3₁₀-helix structure is slowly regaining certain relevance in protein science. The key role of this secondary structure in biological processes has been highlighted in reports over the last decade. In addition, 3₁₀-helices are considered key intermediates in protein folding as well as a crucial structure for the antimicrobial activity of naturally occurring peptaibols. Thus, it is clear that 3₁₀-helices are relevant scaffolds to take into consideration in the field of biomimetics. In this context, this review covers the strategies developed to stabilize the 3₁₀-helix structure in peptide chains, from the incorporation of constrained amino acids to stapling methodologies. In the last section, the use of 3₁₀-helices as scaffolds of interest in the development of bioactive compounds, catalysts for enantioselective reactions, supramolecular receptors, and membrane-embedded signal transducers are discussed. The present work aims to highlight the relevance, sometimes underestimated, of 3₁₀-helices in chemical biology and protein science, providing the tools to develop functional biomimetics with a wide range of potential applications.