PALB2 and invasive ductal breast carcinoma: Given the molecular-functional association of IQGAP1 and BRCA1 and BRCA1 with PALB2 [22], our purpose was to explore the subcellular location and expression levels of IQGAP1 and its relationship with PALB2 in breast invasive ductal carcinoma (IDC) samples from patients with PALB2 functional deficiency because of pathogenic variants in the germ line.