GSTM1 and porphyria cutanea tarda: Whereas, research conducted in the Argentine capital, which evaluated the role of the GSTT1 and GSTM1 variants with porphyria cutanea tarda (PCT) suggested that the presence of the GSTM1 wild allele could predispose the individual with HIV to the development of the disease, since the GSTM1 null genotype presented a significantly lower frequency in the group of HIV patients with PCT (36.84%) when compared with the group that only contained HIV (53.33%) [41].