HSP90AB1 and breast cancer: Notably, the expression of PDL-1 was downregulated in 4T1.2 mammary tumor cells by c-Myc and Oct4-overexpressing 4T1.2 CM in 24 h, as well as the incubation with Eno1, Hsp90ab1, Eef2, and vinculin (Figure 9C).