Second, through the analysis of hypomorphic alleles, we have uncovered a hidden function of lin as a tumor suppressor gene that would otherwise be masked by the pleiotropic effect of a strong/null allele, akin to several gene dosage-dependent tumor suppressors such as ATR (Fang et al. 2004), HDAC1/2 (Heideman et al. 2013), and Dicer (Kumar et al. 2009). The gene discussed is HDAC1; the disease is neoplasm.