How does the use of cell technology make disease eradication possible.

Diseases effect and or can be (mistakenly) caused by our cells. Cell technology allows us to understand more about every molecular step the cell takes to achieve 'everyday' functions - including our immune cells (how it fights foreign invaders), our DNA (which had the instructions for all of our cells functions), etc.

If we can know how our cells and DNA do each specific job, maybe we can alter how they do their jobs to benefit us.

One good example is cancer. A cancerous cell is one that cannot stop diving bc the instruction/gene in the DNA has been messed up. The cancerous cell doesn't even know it's cancerous. If we could fix the erred DNA sequence, theoretically, we could cure cancer.