ERBB2 and colorectal carcinoma: In vitro, oxaliplatin- or 5-FU-selected single-clone CRC cell lines carry very high HER2 copy numbers and face constant drug exposure, so the HER2-Akt/Nrf2 survival axis alone is sufficient to block apoptosis-conditions that do not recapitulate the fluctuating drug levels, immune attack and stromal barriers present in patients (Pirpour Tazehkand et al., 2018; Jang et al., 2023).