According to the tumor cells with different levels of surface marker expression, Kelley’s group successfully used a microfluidic chip with X-shaped structures to classify CTCs bound to MNPs in whole blood [69,70,71,72], which could effectively capture the subpopulations of anti-EpCAM antibody functionalizing MNP-bound CTCs [72]. The gene discussed is EPCAM; the disease is neoplasm.