Another crucial factor is the enrichment of ascites with tumor‐promoting soluble factors, extracellular vesicles and suppressive tumor‐derived immune cells.43 We cultured our propagated tumor cells out of tumor tissue and ascites with 10% ascites supernatant, and in several experiments we added 10 to 20% of ascites supernatant, which did not negatively influence the efficacy of the bsscFv [HER2xCD3] or tribody [(HER2)2xVγ9]. The gene discussed is ERBB2; the disease is neoplasm.