ESR1 and cancer: In addition, the expression of ESR1 mutation is beneficial to the unique transcription profile of tumor progression, indicating that the selected ESR1 mutation may affect metastasis.[70] Transcriptional analysis from this study[70] and other study[71] shows that ESR1 mutation promotes the up-regulation of Hallmark cancer pathway, including estrogen response, p53 pathway and MTORC1 signal transduction, which indicates the role of mutant ER in promoting ET drug resistance and metastatic phenotype.