CD20-Flex BiFP induces infiltration of DCs and CD8⁺T cells in tumor site. Tumor was removed 8 days after tumor inoculation from control Ig-, rituximab-, Flex-Ig-, or CD20-Flex BiFP-treated mice and then were embedded in Tissue-Tek OCT compound and frozen in liquid nitrogen. Tissues were sectioned on a cryostat. CD56⁺ NK cells, CD11c⁺ DC, CD4⁺ T cells, and CD8⁺ T cells were stained by a routine IHC protocol. Representative of 5 tumors in each group. Quantification of IHC images using the NIH ImageJ software package. The values are indicated as percent area in comparison with the staining obtained from the NT group.