Next we examined TP53 status, because more than half of all human cancers, including breast cancers, lose TP53 function[46] and TP53 is a known master regulator of cell-cycle checkpoints.[47] However, TRPS1 silencing had no effect on TP53 expression, as determined using RT-PCR cell cycle arrays. This evidence concerns the gene TRPS1 and breast carcinoma.