The era of molecular analysis rather than descriptive features can be dated to the work of Kurashige (1988) and Kron (1997) who used matK sequencing. Later Gao "et al." (2002) used ITS sequences to determine a cladistic analysis. They confirmed that the genus "Rhododendron" was monophyletic, with subgenus "Therorhodion" in the basal position, consistent with the matK studies. Following publication of the studies of Goetsch "et al." (2005) with RPB2, there began an ongoing realignment of species and groups within the genus, based on evolutionary relationships. Their work was more supportive of Sleumer's original system than the later modifications introduced by Chamberlain "et al.".