ADSL and cancer: SAICAr levels were at the limit of detection in RPE-1 cells and differences could not be assessed (Figure 1—figure supplement 2B), but elevated SAICAr could be readily observed following ADSL depletion in HeLa, potentially due to elevated levels of DNPS enzymes that have been observed in cancer cells (Figure 1—figure supplement 2C; Zurlo et al., 2019; Agarwal et al., 2020; Yamauchi et al., 2022; Taha-Mehlitz et al., 2021).