Rigosertib sodium (ON-01910 sodium) is a multi-kinase inhibitor and a selective anti-cancer agent, which induces apoptosis by inhibition the PI3K/Akt pathway, promotes the phosphorylation of histone H2AX and induces G2/M arrest in cell cycle. Rigosertib sodium is a selective and non-ATP-competitive inhibitor of PLK1 with an IC50 of 9 nM.