PPP1R13B and cancer: Consistent with these observations, ORP100S also protected EML cells and human cord blood CD34+ cells but not cancer cell lines from 5 Gy irradiation in vitro (Figure 2C; Figure S3C, Supporting Information) and suppressed p53 transcription in EML cells and human cord blood CD34+ cells but not cancer cells (Figure 2D; Figure S4, Supporting Information) resulting in lower levels of p53 and the p53‐regulated proteins MDM2, ASPP1, and p21 in irradiated EML cells and human cord blood CD34+ cells but not in any irradiated cancer cell lines (Figure 2E; Figure S3D, Supporting Information).