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. Author manuscript; available in PMC: 2019 Feb 15.
Published in final edited form as: Methods Mol Biol. 2017;1446:25–37. doi: 10.1007/978-1-4939-3743-1_3

Figure 2. Gene Association File (GAF) 2.1 file format described with example elements.

Figure 2.

In the GAF file, each row represents an annotation, consisting of up to 17 tab-delimited fields (or columns). This figure describes these fields in the order in which they are found in the GAF file. Light blue colour denotes non-mandatory fields, and these are allowed to be empty in the GAF file. The cardinality—the number of elements in the field — is denoted with the symbol(s) in curly brackets: {?} indicates cardinality of zero or one; {*} indicates that any cardinality is allowed; {+} indicates cardinality of one or more; {1} indicates that cardinality is exactly one; {1,2} indicates that cardinality is either one or two. When cardinality is greater than 1, elements in the field are separated with a pipe character or with a comma; the former indicates ‘OR’ and the latter indicates ‘AND’. The GO term assigned in column 5 is always the most specific GO term possible.