OXTR and medical procedure: OTR mRNA was detected in up to 95% of human breast cancercell lines (n = 60)129−134 and tissues (n = 57).130,131 OTR was detected at the protein level in 91% of such tissue samples,130,133 although immunohistochemistry results need to be considered cautiouslydue to potential problems related to OTR antibody specificity andlack of appropriate controls.