These preliminary results in 58 PDAC patients suggest that a) higher numbers of CTCs per ml may be associated with an inferior outcome, b) the subtype of CTC with a KRASG12V mutation may be associated with better survival, and c) KRAS mutations in the CTC (and the tumor) can be heterogeneous and can be different from the mutations in the primary. The gene discussed is KRAS; the disease is neoplasm.