A RCC4 cells were transfected with individual siRNA for 72 h. Cystine deprived medium (2 µM, 1% of regular media) was then applied for an additional 24 h before cell viability analysis. Cell viability is normalized to the viability in a regular medium with non-targeting siRNA on each microplate, then plotted against the rank of the viability of each siRNAs. CSAD is a positive control as shown in red squares. SLC39A7 (ZIP7) is shown in green triangles. B, C Gene Ontology (B), and String (C) analysis of 388 candidates were found to essential for ferroptosis on the screen. (FDR: false discovery rate, P < 0.05; p-value test type: Fisher’s exact).