Tmem132 family of five novel transmembrane proteins (a-e) have been associated with multiple human disease conditions such as cranial aneurysm and lung defects. However, their molecular functions remain largely unknown, potentially due to functional redundancy. To study their roles in basic cellular processes, we will use a newly-developed multiplex CRISPR/Cas9 approach to mutate all five Tmem132 genes simultaneously cultured mouse embryonic fibroblasts, and evaluate the survival, proliferation and various signaling pathways in the mutant cells.