PTPRC and neoplasm: Analyzing B cells for the co-expression of the markers B220 and CD138 to detect plasmablasts in their early proliferative stage revealed no changes in the absolute number of this population in spleen tissue in both control and tumor groups on days 0 and 7, whereas a continuous and significantly increase was observed on days 14 and 21, reaching its peak on day 21 compared to the control (Figure 2C) (day 14: p = 0.0341; day 21: p = 0.0003).