[9] Geminin is a nuclear protein made up of about 200 amino acids, with a molecular weight of approximately 25 kDa.

In many cancer cell lines, inhibition of geminin by RNA interference results in re-replication of portions of the genome, which leads to aneuploidy.

In these cell lines, geminin knockdown leads to markedly slowed growth and apoptosis within several days.

[10] However, the same is not true for primary and immortalized human cell lines, where other mechanisms exists to prevent DNA re-replication.

[10] At the start of the S-phase until late mitosis, geminin inhibits the replication factor Cdt1, preventing the assembly of the pre-replication complex.