Discussion of “Sensitivity of a molecular marker based positive matrix factorization model to the number of receptor observations” by YuanXun Zhang, Rebecca J. Sheesley, Min-Suk Bae and James J. Schauer

There is no specific number of samples that ensure a satisfactory PMF analysis. The statement made in this paper with respect to a specific number of samples is only applicable to this data set and should not be applied to any other data set.