Day 103 has 41 protein-coding genes (browser view) and is also the location of an important forensic marker, D4S139.
D4S139 is mentioned in the Starr Report as one of the markers that implicated Bill Clinton in the Lewinsky scandal. It is a microsatellite VNTR that is hypervariable among people (in a room of unrelated people, everyone will have a slightly different number of repeats), so testing several VNTRs at once can serve as a fingerprint. Before sequencing was commonplace and before the completion of the genome, VNTRs were especially important because they show diversity in length without knowing the sequence.
Click here to see all 8646117 letters of Day 103, with D4S139 underlined.