The leucine zipper domain, a typical coiled coil structure, is made up of the c-Fos–c-Jun heterodimer and is a part of the bZIP activator protein-1 (AP-1) transcription factor, which plays a crucial role in numerous cell pathways (proliferation, apoptosis, cell survival, differentiation) [21] and is often associated with numerous diseases, such as cancer and diabetes [22–24], making it an important therapeutic target. Here, JUN is linked to cancer.