Can understanding the "What?", lead us to "Whom?".  If dominos are arranged standing up and are close to each other, when one is tipped over it causes the next one to fall, and the next, and the next...  Something similar is found in living cells which use a domino-like cascade of sequentially activated enzymes to transmit a signal from outside the cell, into the nucleus where changes in gene expression occur.  These sequences are part of the process called "signal transduction".  Dominos fall in this way because they are intentionally placed in certain patterns.  This raises the question of who or what designed the placement and programming of enzyme pathways within a cell?  Uplook Magazine August-September 2011, p.9.