While human deficiency of each of the CBM components has some unique defining clinical features (e.g., gastrointestinal inflammation seen in MALT1 deficiency or susceptibility to Pneumocystis jirovecii pneumonia (PJP) typical for CARD11 deficiency), as testament to their highly synergistic activities, many phenotypic manifestations are shared across these CBM deficiencies. The gene discussed is MALT1; the disease is pneumocystosis.