CCNB1 and Alzheimer disease: However, and in contrast to progenitor cells, cyclin B1 accumulates in postmitotic neurons in AD (Vincent et al., 1997; Yang et al., 2003; McShea et al., 2007), leading to neurodegeneration (Maestre et al., 2008; Veas-Perez de Tudela et al., 2015a).