Fluctuations in daily JAK2V617F allele burden with and without ECC to calculate epithelial cell contamination. (A) dPCR–derived JAK2V617F VAF was measured in daily passive drool saliva samples from patients since starting IFN-α treatment. Patients had either the following initial VAFs: low (8%), mid (45%), or high (78%). (B) Plot of daily sample–derived JAK2V617F VAFs (mean with range) for 1 month, from 13 patients with MPN. Low = baseline VAF of <33%; mid = baseline VAF between 34% to 66%; high = baseline VAF of >67%. (C) Detection sensitivity curves for leukocytes and epithelium when bisulfite converting different amounts of mixed blood and epithelium control DNA. (r² = 0.9525; P = .0009). (D) Corrected JAK2V617F VAF in patients treated with IFN-α using the ECC system, weekly VAF points before (top) and after (bottom) ECC correction of patients treated with IFN-α.