ROR1 and neoplasm: The medium-to-low ROR1 IHC prevalence results we are showing in these three indications may be influenced by particularities from the tissue donors involved in our cohorts, such as treatment, ethnicity, disease stage, etc. An increase in the number of analyzed cases may not dramatically change these prevalence values because the number of cases used were comparable to the number of cases used in other IHC prevalence studies that accurately described different tumour targets [12, 13].