A, Analysis of heterozygous and homozygous loss of canonical PP2A subunits in uterine serous carcinoma samples from the TCGA. Subunits with loss at greater than 50% are highlighted in red. In aggregate, 101 of 109 USC patients harbor some alteration to PP2A. B and C, Dose response curve for UT42Aα-P179R cells expressing WT Aα (B) or OV17RAα-S256F cells expressing WT Aα (C) were treated with Clofarabine with or without LB-100 in increasing doses held at a constant ratio, n=3 biological replicates, error bars ± SD. D, Dose response curves of AN3CA, HEC50B, and KLE cells treated with Clofarabine as measured by MTT at 72 hrs, n=3 biological replicates, error bars ± SD. Clofarabine alone data from figure D included in panels E-G. E-G, Dose response curve for AN3CA (E), KLE (F) or HEC50B (G) cells treated with Clofarabine with or without LB-100 in increasing doses held at a constant ratio, 72hrs, n=3 biological replicates, error bars ± SD. H-J, Calculated EC50 values from the MTT assays in E-G (calculated from the average of all biological replicates). K, Quantification of total C Subunit levels in UT42Aα-P179R terminal efficacy xenograft tumors as measured by western blot. All tumors normalized to the average of two control tumors. Error bars ± SD, (Students T-test, p-values *** < 0.001). L, Quantification of total C Subunit levels in UT89Aα-KO + S256F terminal efficacy xenograft tumors as measured by western blot. All tumors normalized to the average of two control tumors. Error bars ± SD, (Students T-test, p-values * < 0.05). M, Quantification of total C Subunit levels in UT89Aα-KO + P179R terminal efficacy xenograft tumors as measured by western blot. All tumors normalized to the average of two control tumors. Error bars ± SD, (Students T-test, p-values *** < 0.001). N, Quantification of total C Subunit levels in UT42Aα-P179R pharmacodynamic xenograft tumors from Figure 2G. All tumors normalized to the average of two control tumors. Error bars ± SD, (Students T-test, p-values *** < 0.001). Westerns for (K-N) can be found in Supplemental Figure 8.