How can it be said that genes has anything to do with diseases? Disease can be understood as some malfunctioning of cells. So if we understand all cellular functioning as to be due to the control by DNA the root source of diseases can be seen to be errors in the DNA. Of course this exempts the malfunctioning of cells due to infections or injuries. It seems to be the case that scientists have no clue of what, if any, infections causes the majority of diseases. So they concoct this DNA explain it all idea.
But how does neo-Darwinism comes in? Well if you note a well engineered cellular functioning,eg the great body difence system then it is the habit of Darwinists to step in and say that it is all due to evolution via a series of accidents. Such evolution requires that every ingenious thing going on in a living thing must be controlled by DNA. This is because DNA is the point through which natural selection is supposed to take place. This mean that it isn't a surprise that scientists would soon or later amuse themselves that the body's wonder disease fighting and prevention machinery is all due to workings controlled by the DNA. So if we could know the whole of DNA, so they thought, then we will have the recipe for the cures of all diseases! Well, they were wrong!
If on the other hand there is another means through which the cell can carry out its ingenious functions without being controlled by the DNA, as Lipton suggest, then such functioning cannot have evolved the Darwinian way! So that is what is at stake!