ERBB2 and cancer: Accordingly, the most recent ASCO-CAP template updates on 19 March 2025 provided updated guidance for pathologists to report HER2-ultralow, i.e., presence vs absence of staining in IHC 0 (https://documents.cap.org/documents/New-Cancer-Protocols-March-2025/Breast.Bmk_1.6.0.0.REL.CAPCP.pdf).