in contrast , smooth muscle cells grown within matrices of collagen type i , on collagen type iv , or on basement membrane matrigel had a vv myo of 30.7 +/- 1.5 % , 30.8 +/- 4.2 % , and 32.1 +/- 3.1 % , respectively .
C0009333
collagen type iv
C0004799
basement membrane