The phase 3 TyTan trial that tested lapatinib as a second-line treatment in Asian patients with advanced GC showed a better survival benefit in the HER2 IHC 3+ subgroup (PFS 5.6 vs. 4.2 months; P = 0.0101) but failed to significantly improve OS in the total population (mOS 11.0 vs. 8.9 months; P = 0.104), possibly because the overall population of HER2 IHC 0/1+ patients (35%) was higher [90]. Here, ERBB2 is linked to gastric cancer.