Properties of a hybrid between lines sensitive and insensitive to contact inhibition of cell division

Abstract
Hybrid cell lines have been prepared between 3T3, a line highly sensitive to contact inhibition of division, and cl 1‐D, an L cell derivative which is not sensitive. A number of hybrid clones isolated were found to be quite sensitive, indicating that in this respect the 3T3 behavior is the more fully expressed in the hybrid. On serial subculture, the hybrid lines gave rise to variants less sensitive to contact inhibition.