ROS1 is a transmembrane protein with tyrosine kinase activity with putative function as a growth or differentiation factor receptor. ROS1 expression is limited in normal tissues to occasional staining cerebellum, stomach, small intestine, colon and kidney. Rearrangements of the ROS1 proto-oncogene were originally detected in glioblastoma and cholangiocarcinoma. ROS1 fusion partners include CD74, SLC34A2 and SDC4, leading to oncogenic transformation. ROS1 neoplastic transformation is widely studied in non-small cell lung cancer (NSCLC). While ROS1 is undetectable in the normal lung, studies have described ROS1 rearrangements in 1-2% of NSCLC by FISH. Recent reports have demonstrated strong correlation between ROS1 immunoreactivity with FISH positivity
ROS1 is a transmembrane protein with tyrosine kinase activity with putative function as a growth or differentiation factor receptor. ROS1 expression is limited in normal tissues to occasional staining cerebellum, stomach, small intestine, colon and kidney. Rearrangements of the ROS1 proto-oncogene were originally detected in glioblastoma and cholangiocarcinoma. ROS1 fusion partners include CD74, SLC34A2 and SDC4, leading to oncogenic transformation. ROS1 neoplastic transformation is widely studied in non-small cell lung cancer (NSCLC). While ROS1 is undetectable in the normal lung, studies have described ROS1 rearrangements in 1-2% of NSCLC by FISH. Recent reports have demonstrated strong correlation between ROS1 immunoreactivity with FISH positivity