Anti-TSPAN15 was incubated with cellular protein extracts from KYSE30 cells, and protein A/G agarose beads were then added. Recovered proteins associated with TSPAN15 or IgG were resolved by gel electrophoresis. The bands specific bind to TSPAN15 were excised, and proteomics screening was accomplished by mass spectrometry analysis on a MALDI-TOF-MS instrument (Bruker Daltonics).