Expression of cancer stem cell markers CD133, c-Myc, and nestin in frozen sections of LN229 tumors revealed by immunohistochemistry. Nuclei were counterstained with DAPI. All nanobioconjugates caused marked inhibition of the expression of all targets, especially the dually targeted nanobioconjugate (P/Cetu/EGFR/CK2α). Representative pictures are shown. Scale bar = 10 μm. AON - antisense oligonucleotide, PBS - phosphate-buffered saline, Cetu - cetuximab, CK2α - catalytic α subunit of protein kinase CK2, EGFR - epidermal growth factor receptor, P/Cetu/CK2α - nanobioconjugate with AON against CK2α, P/Cetu/EGFR - nanobioconjugate with AON against EGFR, P/Cetu/EGFR/CK2α - nanobioconjugate with AONs against both EGFR and CK2α.