Breast cancer remains one of the most prevalent cancers and a leading cause of cancer-related deaths among women worldwide. The Hippo signaling pathway, which includes key components such as large tumor-associated kinases, and the transcriptional coactivators Yes-associated protein (YAP) and TEAD4, plays a critical role in regulating cell growth. TEAD4, a member of the TEAD family, is a transcription factor that interacts with YAP to regulate the expression of genes involved in cell proliferation, migration, and survival. Dysregulation of the Hippo pathway results in the accumulation of YAP/TEAD4, leading to abnormal gene expression that promotes tumor progression. Recent studies have identified TEAD4 as a crucial player in breast cancer development. In our research, we utilized the CRISPR-Cas9 system to design specific single guide RNAs (sgRNAs) that target and knock out TEAD4 in breast cancer cells. This genetic manipulation showed promising results in inhibiting cell proliferation, migration, and invasion. Furthermore, our bioinformatics analysis reinforced the critical role of TEAD4 in tumorigenesis.