CYP1A1 and rheumatic heart disease: Our analysis identified a subgroup of six DEGs out of 171 DEGs characteristic of the RHD vs. ARF group that are known to play a role in tryptophan metabolism (a pathway that houses tryptophan biosynthesis as a sub-pathway), including THP1, THP2, AFMID, CYP1A1, CYP1A2 and ALDH7A1 to be downregulated indicating that tryptophan metabolism may get further downregulated during the progression of ARF to RHD.