For instances, in a recent published study in 111 assessable breast cancer patients, the response rate to single agent trastuzumab for those expressing 3+ versus 2+ was 35% and 0% respectively [26], while in lung cancer, a phase II trial of gemcitabine-cisplatin with or without trastuzumab in HER2-positive patients, yet there was not overall differences in response between both arms, the benefit was limited to those with 3+ of expression with the Hercep Test. Here, ERBB2 is linked to lung cancer.