CCN1 and breast cancer: Studies have shown that downstream of MST and LAST in the Hippo signaling pathway, the transcriptional co-activators YAP and TAZ bind to members of the TEAD family of transcription factors to regulate the expression of downstream target genes, such as connective tissue growth factor (CTGF/CCN2) and cysteine-rich protein 61 (CYR61/CCN1), and the junctional CTGF/CCN2 complex plays an important role in promoting osteoclast formation and osteolytic metastasis in breast cancer (75).