Definition

Describes cells that have a protein called ROS1 on their surface. In cancer, it is also used to describe cells that have a change in the structure of the ROS1 gene or a ROS1 fusion protein on their surface. In normal cells, ROS1 is involved in cell signaling and cell growth. Cancer cells that have the changed ROS1 gene or the ROS1 fusion protein may grow more quickly. Knowing whether a cancer is ROS1 positive may help plan treatment. Cancers that may be ROS1 positive include non-small cell lung cancer, a type of brain cancer called glioblastoma multiforme, and cancers of the bile duct, ovary, stomach, colon, and rectum.