FOXM1 and cancer: For most inhibitors, even those shown to bind to FOXM1c or FOXM1b, it is not known exactly where they bind to FOXM1 and which isoforms are being targeted, but in most cancers, FOXM1a and FOXM1d are at very low levels, so when total cellular FOXM1 levels are reduced upon treatment with inhibitors or PROTACS, this generally represents largely FOXM1c and FOXM1b.