ULBP2 and breast carcinoma: Longer drug treatment increased the soluble forms of MICA and ULBP2, the two molecules reportedly cleaved and released into the extracellular space as negative feedback ligand-mediated NK regulation [14], in culture medium of breast carcinoma cells at 48 and 72 hours after docetaxel treatment compared to untreated cells (Supplementary Figure S1), partly explaining their reduction on the cell membrane.