1. Study all the genes in a genome. 

2. Genes concerned with cancer can be found and sequenced. Study the transcripts in a particular tissue or organ or tumor

3. Study of interaction of various genes, proteins and their interaction.

Future challenges of human genome project are 

1. Being an enormous task it will require the expertise and creativity of  many people from varied disciplines in both the public and private sectors worldwide.
2. New high-throughput technologies and a huge amount of money will be needed for the same.