TSPAN8 and neoplasm: Since invasive Tspan8-positive cells also expressed peanut agglutinin lectin (PNA)-binding sites [23], reported to be associated with a propensity for dermal invasion [50], in vivo metastasis [51], and with poor clinical outcome of patients [52, 53], it is conceivable that Tspan8 identifies tumor cell subpopulations with low adhesive potential, able to escape from the primary tumor and move unhindered in the matrix environment to circulate and metastasize.