STAT3 and breast cancer: LIF‐YAP is an axis that governs not only breast cancer metastasis and cell polarity47, 48 but also embryonic stem cell self‐renewal.49 Astrocyte maturation, differentiation and angiogenesis are promoted by introducing LIF19, 20, 50 via different signalling pathways, such as signal transducer and activator of transcription‐3 (STAT3).51 However, YAP‐LIF signalling has not yet been well established between vessels and related astrocytes.