Figure S1. LAPC-4 and CWR22RV1 are telomerase-positive ALT-negative cell lines. Figure S2. ATRXKOs were generated in LAPC-4 and CWR22Rv1 cells. Figure S3. Representative telomere restriction fragment (TRF) southern blots and signal intensity traces. Figure S4. TERT and TERC expression levels. Figure S5. CRISPR cas9 genome editing strategies targeting the TERC locus. Figure S6. RT-qPCR validation of genes differentially expressed in microarray.