HIV-1 replicates in ninja-like ways. The virus slips through the membrane of vital white blood cells. Inside, HIV-1 copies its genes and scavenges parts to build a protective bubble for its copies. Scientists don't understand many of the details of how HIV-1 can fool our immune system cells so effectively. The virus infects 1.2 million people in the U.S. and 37 million people worldwide in 2018. Supercomputers helped model a key building block in the HIV-1 protective capsid, which could lead to strategies for potential therapeutic intervention in HIV-1 replication.