RASSF1 and ductal breast carcinoma in situ: As shown in Figure 2A, RASSF1A gene expression in DCIS.com cells varied somewhat across the stiffnesses examined, but with a significant (p < 0.01) upward trend in stiffnesses approaching between 50–150 Pa (corresponding to BiRADs 1, which contrasted a significant (p < 0.0001) downward trajectory of gene expression when stiffness increase through stiffnesses relevant to BiRADs 4 (~5 kPa) to beyond normal mammary stiffness (50 kPa).