ALDH1A2 and neoplasm: Having identified the different cell populations in each patient immune infiltrate sequenced, we found that a low number of monocytic cells were ALDH1A2+ (Figure 6A), a result which was surprising in view of the gene expression array performed on the THP1 cell model or the protein expression by Western blots and immunohistochemistry of the sequenced tumor samples (Figure 3A and Figure 4A).