Table 1.

The possible scenarios for peptide assignment to Human or Mouse.

Human unique peptides	Mouse unique peptides	How razor peptides are assigned to a protein group:
Yes	Yes	Unique peptides used to report a quantification value for each human and mouse protein. Razor peptides contribute only to the protein group with largest number of peptide identifications.
Yes	No	Unique and Razor peptides all used to report a value for Human protein group; no mouse reported.
No	Yes	Unique and Razor peptides all used to report a value for Mouse protein group; no human reported.
No	No	All razor peptides are used to report a Human/Mouse value for protein