Fig. 1

Comparison of IHC, FISH and qRT-PCR in ROS1 rearrangement and non-rearrangement cases (a–d). The H&E staining, IHC, FISH and qRT-PCR results of a non-rearrangement case. a The case presented acinar and papillary patterns in H&E staining (200×); b IHC showed no staining in tumor cells (200×); c, d it was confirmed by FISH and qRT-PCR as non-rearrangement, respectively; e–h A case with weak and focal ROS1 IHC staining. e The case presented acinar pattern in H&E staining (200×); f IHC showed weak to moderate focally staining in about 40 % tumor cells (200×); g, h it was also confirmed as non-rearrangement by FISH and qRT-PCR, respectively; i–l A case with diffusely moderate IHC staining. i The case presented papillary and micropapillary patterns in H&E staining (200×); j IHC showed moderate staining with cytoplasmic and focal granular patterns in about 80 % tumor cells (200×); k and l it was proved as ROS1-rearrangement by FISH and qRT-PCR, respectively; m-p A case with diffusely strong IHC staining. m The case presented papillary and micropapillary pattern in H&E staining (200×); n IHC showed diffusely strong staining with cytoplasmic, membrane and granular patterns in about 90 % tumor cells (200×); o, p it was also proved as ROS1 rearrangement by FISH and qRT-PCR