Table 1. Upper part: Top ten proteins of list 1; Associated with unstimulated FGFR1. Proteins significantly (p < 0.05) enriched in S1 (U2OS-R1-BirA* cells) compared to C1 (U2OS-R1 cells) and C2 (U2OS-R1 cells co-expressing BirA*). Proteins in red have previously been associated with FGFR1 as reported in BioGRID 3.4 (35). An arrow pointing upwards means that the protein was further enriched in samples stimulated with FGF1 whereas an arrow pointing down indicate that the protein was reduced in samples stimulated with FGF1. In bold, protein investigated further in this study. Middle part: Top 15 proteins of list 2; Increased association with FGF1 stimulation. Proteins significantly (p < 0.05) enriched in S2 (U2OS-R1-BirA* cells, FGF1 stimulated) compared to C1 (U2OS-R1 cells), C2 (U2OS-R1 cells coexpressing BirA*), C3 (U2OS-R1 cells coexpressing BirA*, FGF1 stimulated), and S1 (U2OS-R1-BirA* cells). Proteins in red have previously been associated with FGF signaling (35, 46, 53). Lower part: Top ten proteins of list 3; FGF induced gene expression. Proteins significantly (p < 0.05) enriched in C3 (U2OS-R1 + BirA* cells, FGF1 stimulated) compared to C1 (U2OS-R1 cells) and C2 (U2OS-R1 cells co-expressing BirA*). Proteins in red have previously been reported to be expressed upon FGF1 stimulation while proteins in blue were previously shown to be downregulated in response to FGF1 (54).