NPB and nasopharyngeal carcinoma: As indicated above, free bile acids are preferentially observed with the current method and 3β,5α,6β-triHBA was detected in NPC (1–3.5 ng/mL), NPB (1–2 ng/mL) and one of the two LALD (0–1.5 ng/mL) patient samples, but not controls or carriers (≤0.1 ng/mL) (Fig. 3B).