To test this hypothesis, we transfected U2OS human osteosarcoma cells with vectors carrying histone 2B-green fluorescent protein (H2B-EGFP), H2B-Venus or H2B-mCherry fusion protein expression cassettes along with a neomycin resistance cassette followed by G418 (neomycin) selection to generate a large number of stable U2OS sub-lines, or clones. The gene discussed is H2BC21; the disease is osteosarcoma.