A subsequent study focusing on 49 HER2- overexpressing NSCLC (29 IHC 2+ and 20 IHC 3+) found an ORR of 20% in the IHC3+ subgroup compared to no response in the IHC2+ subgroup, whereas the median PFS and OS were similar (2.6 vs. 2.7 months and 12.2 vs. 5.3 months, respectively). Here, ERBB2 is linked to non-small cell lung carcinoma.