ERBB2 and breast cancer: For this purpose, (Figure 1A), we extracted RNA from ERBB2+ and non-ERBB2+ breast cancer cells (BT474, MCF7, MDA MB231, and T47D), performed cDNA synthesis, performed PCR amplification of the cDNA, and then sequenced them with ERBB2 3’UTR primers by Sanger sequencing (Supplementary Figure S3A–E).