Controllable transcription

A method for controlling transcription of a genetic sequence in a cell, comprising:

• a) inserting into a cell a gene encoding a transcriptional regulator protein into a first genetic safe harbour site;
• and
• b) inserting into the cell an inducible cassette into a second genetic safe harbour site, wherein said inducible cassette comprises a genetic sequence operably linked to an inducible promoter, and said promoter is regulated by the transcriptional regulator protein;
• wherein said first and second genetic safe harbour sites are different;
• and wherein the inserting of each of steps a) and b) is performed in vitro via targeted insertion using a clustered regularly interspaced short palindromic repeats (CRISPR), a zinc-finger nuclease (ZFN), or a transcription activator-like effector nuclease (TALEN).