ESR1 and cancer: Between January 2010 to November 2019, a total of 3360 paired cases (MG and corresponding US) were obtained (as shown in Fig. 1a, b), and these cancer cases were grouped into 4 molecular subtypes based on the information of ER, PR, HER2 and Ki67 from IHC findings and silver-enhanced in situ hybridization (SISH) test (as shown in Fig. 1c).