Additional file 1: Table S1. Primers for construction of the truncated mutants of HA-fused SH3BGRL. Supplemental Figure S1. SH3BGRL expresses in various breast cancer cell lines. Supplemental Figure S2. SH3BGRL prolongs HER2 stability and duration on cell membrane. Supplemental Figure S3. SH3BGRL promotes cell cycle progression. Supplemental S4. SH3BGRL renders drug resistance. Supplemental S5. Targeting SH3BGRL represses the xenografted tumor formation. Supplemental Figure S6. Targeting SH3BGRL represses cell proliferation and enhances cell apoptosis in xenografted tumors. Supplemental Figure S7. SH3BGRL activates HER2 to promotes tumor progression. Supplemental Figure S8. Relevance of SH3BGRL and HER2 in breast cancer tissues.