ROS1 and non-small cell lung carcinoma: However, recent studies have explored the mutational landscape of NSCLC occurring in the young, providing evidence that these tumors are enriched in targetable genetic alterations, such as ALK and ROS1 rearrangements (whose frequency peak of incidence occurs in patients <40 years of age) and HER mutations (whose frequency peak of incidence occurs in patients of 41-50 years), while KRAS and BRAF mutations are more frequent among older patients [23].