Note that the cell-cycle pathways (displayed in italics in Table 2) are implicated also in ever smoking. These pathways relate to the Anaphase-Promoting Complex/Cyclosome-mediated degradation of Cdc20 and other APC/CCdh1 targeted proteins. Although none of these pathways is associated with both smoking phenotypes, they are inter-connected, forming chains of pathways governing different stages of cell division. Especially enriched in ever smokers is the conversion from APCCdc20 to APCCdh1 in late anaphase pathway (P=1.61E-07), while in the quantity smoked analysis, enrichment signals come from the autodegradation of Cdh1 by Cdh1:APC/C pathway (P=4.28E-17) and from the APC/CCdh1-mediated degradation of Cdc20 and other APC/CCdh1-targeted proteins in late mitosis/early G1 pathway (P=1.99E-16). We identified no significant pathways for age at initiation or smoking cessation.
