The PMA and AgNPs-CIT effects on the viability of the MCF-7 cell-lines were determined invitro. The MCF-7 cell-lines (1 × 106/mL) were placed in 35-mm culture dishes (Becton-Dickinson, Franklin Lakes, NJ, USA) in DMEM medium, or serum-starved for 12 hr/overnight. The MCF-7 cell-lines were cultured without PMA, or AgNPs-CIT served as controls. The cells were treated with various doses of AgNPs-CIT (0.5 to 160 μM) for 24–48 h of the incubation, and the cytotoxicity was examined using the CytoTox-Glo™, Cytotoxicity Assay Kit (Promega, Madison, WI, USA) as described.35 (link) In another set of experiments, MCF-7 cell-lines were pretreated with different doses of AgNPs-CIT (0.5–10 µM) for 2 h before its stimulation with PMA (0.5 µM) according to the reported procedure.36 (link),37 (link)