The mathematical and computer modelling of functioning regulatory
mechanisms (regulatorika) of cellular communities is actual at solving the many bio-
logical problems which are connected with the quantitative evaluation of an organismfs
cells behaviour, united by performing some general functions. In this work we consider
the mathematical modelling method for the regulatorika of cellular communities based
on the functional-differential equations of a function unit of cellular communities in
multicellular organisms. Results, obtained applying this approach to the quantitative
analysis of CD4 lymphocytes number regulatorika in HIV/AIDS, as well as thyroid
gland follicles cellular communities in malignant neoplasms are given.