Apoptosis is a highly orchestrated, genetically regulated form of cell death, the impairment of which is crucial in breast cancer (BC) development and progression. BCL2L12, a member of the BCL2 family of apoptosis-related genes, has been studied in various malignancies, revealing its potential role as a tumor biomarker. It has been recently found that BCL2L12 is subjected to alternative splicing, resulting in the generation of 13 alternatively spliced variants. The aim of this study was the quantification of BCL2L12 splice variants 1 and 2 (v.1 and v.2) expression at the mRNA level and the assessment of their biomarker potential in BC