TP53 and breast cancer: Furthermore, to determine the role of mutant p53 in the TME, we engineered 4T-1 cells (murine breast cancer cells) to overexpress trp53R270H (p53R273H in human), trp53R172H (p53R175H in human) and their respective negative control group detected by WB (Fig. S4C) and injected an equal amount of negative control and trp53R270H/trp53R172H -expressing 4T-1 cells into the mammary fat pad of BALB/c mice.