IL4 and tuberculosis: Second, the study was limited in that any within-the-group comparisons and meta-analyses were unable to be carried out concerning subgroups of TB such as pulmonary versus extrapulmonary, cavitation versus non-cavitation, smear-positive versus smear-negative, and HIV-infected TB versus HIV-uninfected; therefore, it was not possible to examine the link of the disease outcome and the IL-4 profile due to the available data containing fewer observations.