The article discusses the TRIMa, part of the tripartite motif (TRIM) protein family needed for natural immunity of retroviruses. Accordingly, TRIM family holds RING domains, B-box domains and coiled-coil region which are necessary to identify and fight viruses. The study of Kar and Langelier with colleagues uses TRIM5a of rhesus monkey with RING domain switch to TRIM21 related human protein. The combat of TRIM5a by tearing capsids and role of oligomerization in the process is to be clarified.