Effect of storage time of paraffin sections on the expression of PD-L1 (SP142) in invasive breast cancer.

"Declarations Ethics approval and consent to participateApproval of the research protocol by an Institutional Reviewer Board: All tissues and data were retrieved under the permission of the institutional research ethics board of the Fourth Hospital of Hebei Medical University with the declaration number of 2020KY112. Informed consentThe experiment does not involve interaction with human subjects and/or the use of personally identifiable information. Informed consent was not required and patient information was not disclosed when existing pathological materials were used.Registry and the Registration No. of the study/trial: 2020KY112. Animal StudiesN/A. Consent for publicationNot applicable. Competing interestsThe authors declare that they have no competing interests. Competing interests The authors declare that they have no competing interests."

"Funding information This research did not receive any specific grant from funding agencies in the public, commercial or not-for profit sectors."

"Declarations: Ethics approval and consent to participateApproval of the research protocol by an Institutional Reviewer Board: All tissues and data were retrieved under the permission of the institutional research ethics board of the Fourth Hospital of Hebei Medical University with the declaration number of 2020KY112.: Informed consentThe experiment does not involve interaction with human subjects and/or the use of personally identifiable information. Informed consent was not required and patient information was not disclosed when existing pathological materials were used.Registry and the Registration No. of the study/trial: 2020KY112.: Animal StudiesN/A.: Consent for publicationNot applicable.: Competing interestsThe authors declare that they have no competing interests. Informed consent: The experiment does not involve interaction with human subjects and/or the use of personally identifiable information. Informed consent was not required and patient information was not disclosed when existing pathological materials were used.: Registry and the Registration No. of the study/trial: 2020KY112."