Moreover, decreasing heterochromatin formation via HP104/+ with reducing HP1a levels by half, as in rasG12V, HP1a+/−; csk−/− animals, with HDS, showed no improvement in tumor growth and eclosion/survival of tumor-bearing flies compared to those of rasG12V; csk−/− tumor-bearing flies fed HDS (Supplement Fig. 3). The gene discussed is CSK; the disease is neoplasm.