GOPC and glioblastoma: Endogenous ROS1 rearrangements were first observed in the human GBM cell line U118MG, in which an interstitial deletion of 240 kilobases on 6q21 region is responsible for the fusion of exon 7 of FIG (Fused In GBM, location 6q22.1) (also known as GOPC, Golgi-associated PDZ and coiled-coil motif containing) with exon 35 of ROS1.