ERBB2 and neoplasm: However, the corresponding IHC on the tissue biopsy showed low to moderate membrane immunoreactivity to HER2 antibody in 50% of tumor cells (Table S1), compatible with the EV‐RNA sequencing data, and overall suggesting a potential HER2 overexpression regulation at the transcriptional or post‐transcriptional level (Daemen & Manning, 2018; Kraus et al., 1987; Li et al., 2020; Liu et al., 2018; Wang et al., 2017).