PDGFC and neoplasm: PDGFC RNAscope, using a human-specific probe (Extended Data Fig. 10c), confirmed quantitative PCR with reverse transcription (RT–qPCR) analysis of isolated tumor cells (Extended Data Fig. 6b), showing upregulated PDGFC expression in ZR-75-1 primary tumor cells but low-level PDGFC expression by DTCs, again supporting the contention that dormant DTCs are PDGF-Clo.