CD40 and breast cancer: When the demonstration of CD40 variant expressions is technically considered, it can be mentioned that not showing the variants by sequencing and not quantifying the expression differences of CD40 variants using quantitative real-time PCR is among the handicaps of the experimental assay.Therefore, no further quantitative evaluation of gene expression has been performed due to the absence of CD40 expression in some of the breast cancer cell lines and for the purpose of displaying the existence of CD40 variants (V1–3) only.