*4.8. FACS Sorting and Processing of Sorted Cells*

Single cell suspensions of tumor and adjacent healthy renal tissue were stained with an antibody cocktail containing CD33 BV510 (BD, 563257), MerTK BV421 (Biolegend, 367603), CD45 AF700 (Biolegend, 368513), CD64 BV605 (Biolegend, 305033), CD326 PE-CF594 (BD, 565399), HLA-DR APC-Cy7 (Biolegend, 307658). Cell suspensions were sorted using a FACS Aria (BD) FACS sorter, resulting in CD45−/CD326<sup>+</sup> epithelial cells and CD45+/CD33+/HLA-DR+/CD64+/MerTK<sup>+</sup> MΦ from tumor and healthy tissue.

Cells were harvested for AAS (5000 cells) or used for RNA isolation (1000 cells). RNA isolation and transcription were performed using the RNeasy Micro Kit (Qiagen, 74004) and Sensiscript RT Kit (Qiagen, 205211) according to the manufacturer's kit protocols.

## *4.9. Cell Culture*

Human renal cancer cell lines CAKI-1 and 786-O cells (kindly provided by PD Dr. Anja Urbschat) were cultured in Dulbecco's modified Eagle's medium (Gibco, Dreieich, Germany, 41965) supplemented with penicillin 100 U/mL (Sigma-Aldrich, P4333), streptomycin 100 mg/mL (Sigma-Aldrich, S8636), and 10% FCS (Capricorn Scientific, Ebersdorfergrund, Germany FBS-11A). Cells were regularly tested for mycoplasma contamination using Venor GeM Classic (Minerva Biolabs, Berlin, Germany, 11-1100).

#### *4.10. Tumor Tubular Epithelial Cell Isolation*

Human tubular epithelial cells (TTEC) were isolated as previously described [52]. Briefly, tumor tissue was minced, digested with collagenase/dispase (1 mg/mL), and passed through a 106 μm mesh. The tumor tissue solution was then incubated with collagenase (1 mg/mL), DNase (0.1 mg/mL) and MgCl2 (5 mmol/L). Cells were seeded on FCS-precoated plates and grown in M199 medium (Sigma Aldrich, M4530), supplemented with penicillin (100 U/mL), streptomycin (100 mg/mL), and 10% FBS. Meropenem (100 μg/mL, Sigma Aldrich, M2574) was added to the culture medium for the first 2–3 days after isolation. Passages from two to four were used for experiments.
