ERBB2 and non-Hodgkin lymphoma: Nevertheless, it has been roughly established that 30–60% of patients with indolent non-Hodgkin lymphoma (NHL) are resistant to rituximab, 70% of patients with HER2-positive breast cancers show intrinsic or secondary resistance to trastuzumab and only 15–20% of patients with head and neck cancer respond to cetuximab [67,68].