occurs_at occurs_at GOREL:0000501 occurs_at fission_yeast_phenotype This relation is not constrained with respect to whether the place where an event occurs completely surrounds, or is adjacent to, the location indicated. Example: chromatin silencing at centromere unfolds_around centromere : Repression of transcription of centromeric DNA by the formation of heterochromatin. Used in FYPO to identify a position where a phenotype is observed or relevant, usually a DNA or RNA sequence feature specified by a SO ID.