SH2D3A and infection: Chikungunya infection produces two viral RNA species that are capped by nsP1; the full-length 11.8 kbp positive-sense genomic RNA (gRNA), and a subgenomic RNA (sgRNA) of 4.3 kbp that is transcribed from the second open reading frame at later stages of infection and encodes only the structural polyprotein (19, 20).