PTPN22 and invasive ductal breast carcinoma: CNT: carbon nanotube, MWCNTs: multi-walled carbonanotubes, SWCNTs: single-walled carbonanotubes, DOX: Doxorubicin, ROS: reactive oxygen species, FA: folic acid, LyP-1: cryptic CendR peptide, MDA-MB-231: cell line (isolated at M D Anderson from a pleural effusion of a patient with invasive ductal carcinoma) is commonly used to model late-stage breast cancer.