PTPA and neoplasm: LB-100 is a small molecule inhibitor of the PP2AC subunit generated in 2016 and has recently completed a phase I clinical trial for the treatment of solid tumors in combination with docetaxel, although PP2A is widely accepted as a tumor suppressor.301 LB-100 inhibited homologous recombination repair in part by increasing the phosphorylation of the PP2A substrate CDC25C at the threonine 130 site.