TIMP3 and breast carcinoma: However, in breast cancer, TIMP-3 mRNA was found by in situ hybridization to be expressed predominantly in the peritumoral stroma [22], whereas its clinicopathological and prognostic value has been evaluated in relation to the expression levels of TIMP-3 mRNA and measured by methods that did not distinguish the cancerous from the stromal origin of the transcripts [23,24].