HSF4 and small cell lung carcinoma: Our recent data showed that both the CellSearch and the ISET can detect CTM in blood samples from small cell lung cancer (SCLC) patients; ISET had a greater capability of isolating CTM with respect to CTM number and size, which might reflect the reduced requirement for manipulation of the blood sample and/or size constraints of CTM captured by immunomagnetic beads, and/or absent expression of the CellSearch capture and identification antigens, EpCAM and cytokeratins by SCLC CTM (Figure 1B).