'....normally develop into soldiers or workers depending on the levels of the "juvenile hormone": if levels are high the ants become soldiers, while if they are low they become the smaller worker ants. In the species that produce supersoldiers there is a second high threshold of the juvenile hormone, above which the larvae develop into the larger supersoldiers.'

If you gave a normal cat unchecked growth hormones it would not resemble a tiger - it would die. Its body is not designed to be that large - look at case reports of humans with growth disorders, they have all sorts of very serious issues simply from being larger than designed.