CCND1 and invasive carcinoma: In order to simulate the stiffness range of the in vivo normal tissue and invasive carcinoma, that was reported to be from 3 to 13 kPa [36], MDAPSFs with different stiffnesses were produced using 2.25, 4.5 and 9 % (w/v) of PEGDa and the cyclin D1 expression was assessed.